List of Gastrointestinal Agents

Gastrointestinal Agents

The gastrointestinal tract or digestive tract also referred as the GI tract or the alimentary canal. Gastrointestinal System is responsible for the breakdown and absorption of various foods and liquids needs to sustain life.

GI tract starts with the mouth and proceeds to the esophagus, stomach, small intestine (duodenum, jejunum, ileum), and then to the large intestine (colon), rectum, and terminates at the anus. This section covers the discussion about certain important topics :

  1. Acidifying Agents or Acidifiers
  2. Antacids
  3. Protective and Adsorbents
  4. Saline Cathartics

Acidifying Agents Or Acidifiers

Acidifying agents are the inorganic chemical substances that either produce or increase acid. These chemicals increase the level of gastric acid in the stomach when ingested, thereby decreasing the stomach pH. It is broadly classified into four categories:-

Read and Learn More Pharmaceutical Inorganic Chemistry Notes

  1. Gastric Acidifiers: These are the drugs which are used to increase the acidity of the stomach in patients suffering from Achlorhydria or Hypochlorhydria (absence or insufficient quantity of HC1 acid in the gastric secretion). It responds to stimulation by histamine. The Achlorhydria patients are of two types
    1. Those who do not respond to histamine phosphate stimulation for the release of HC1.
    2. Those who respond to histamine phosphate stimulation for the release of HC1 in the stomach. In either of the cases, the G.I. disturbances i.e. frequent bowel movement, mild diarrhoea, epigastric pain and sensitivity to spicy foods are the common symptoms. It is used to control the pH of the acidic stomach (pH 1.5-3.5). This condition is best treated by the administration of HC1 acid.
  2. Urinary Acidifiers: These are the drugs which are used to remove acidic urine from the body or to maintain the pH of the urine. These acidifiers are widely used to cure some types of urinary tract infections.
    For example: Many bacterias are grown badly in acidic urine as far as urine is cemed. Hexamine only acts as antiseptic when the urine is acidic. In acidic media, hexamine itself break up into ammonia and formaldehyde.
  3. Systemic acidifiers: These are the drugs which are able to neutralise the alkaline body fluids, especially blood or to maintain the pH of all parts of the body. It is used to treat patients suffering from systemic alkalosis.
  4. Acid: These are used as pharmaceutical aids in the preparation of medicaments, laboratory quality control.

Hydrochloric Acid

Molecular formula ;HCl                    Molecular Weight:36.46

Synonym: Spirit of Salt, Muriatic acid

Preparation

It can be prepared by the action of cone. Sulphuric acid on Sodium Chloride and passing the liberated Hydrogen Chloride through water.

HYDROCHLORIC ACID

In this method, the hydrogen and chlorine obtained in the electrolysis of sodium chloride in the manufacture of caustic soda are burnt, preferably using quartz bunsen burners.

HYDROCHLORIC ACID

100% pure HC1 is formed in this method

Properties

  1. It is nearly colourless clear and fuming liquid.
  2. It possesses pungent odour.
  3. It is soluble with water and alcohol.
  4. It is a strong acid and attacks metals, forming the hydrochlorides with the evolution of gas.

Chemical Properties

1. It reacts with Sodium metal which results in the formation of sodium chloride and liberates hydrogen gas.

Chemical Properties Of Hcl

2. It is oxidised by strong’ oxidising agents liberating chlorine gas.

Chemical Properties Of Hcl 1

Assay

An accurately weighed sample of the add is diluted with water and titrated with 1M NaOH using methyl red solution as the indicator. End point is the appearance of a faint yellow colour.

Storage

It is stored in well dosed container of glass or other inert material at a temperature not exceeding 30°C.

Uses

  1. It is used as a Pharmaceutical Aid.
  2. It is also employed as an atidifying agent or addifier.

It is also used to inactivate the proteolytic enzyme, pepsin. Certain antadds like Sodium Bicarbonate which are water soluble may raise it pH above 7. The continual hyperacidity may lead to peptic or duodenal ulcer.

Test for Purity

It has to be tested for As, heavy metals, bromides, iodide, sulphate & free iodine.

Ammonium Chloride

Molecular formula: NH4Cl                      Molecular Weight: 53.9

Ammonium chloride contains not less than 99.5% of NH4C1, calculated with referene to substance dried over silica gel for 4 hours.

Preparation

  1. It is prepared by purifying the crude product by sublimation or by boiling ammonium sulphate solution with sodium chloride in the equivalent proportions.
  2. Neutralization of HC1 acid with ammonia and evaporation of solution to dryness yield ammonium chloride.

Properties

  1. It is white, fine or coarse crystalline powder.
  2. It is having a cooling saline taste.
  3. It is odourless.
  4. It is sligthly hygroscopic.
  5. It is soluble in 2.6 parts of H20, 1.4 parts of boiling water & 100 parts of alcohol.

Test for Purity

Test for arsenic, heavy metals, lead, iron, barium sulphate, thiocyanate, loss on drying and non-volatile matter.

Assay

Weigh accurately about 0.2g, dissolve in 40ml of H2O, add 3 ml of Nitric acid, 5 ml of Nitrobenzene & 50 ml of 0.1N Silver nitrate, shake vigorously for 1 minute & titrate with 0.1N
ammonium thiocyanate using 2ml of solution of ferric ammonium sulphate as indicator.

Each ml of 0.1N silver nitrate is equivalent to 0.005349g of NH4Cl.

Uses:

  1. It is used as an expectorant.
  2. It is used as a diuretic & systemic acidifying agent.
  3. It is used to maintain the urine at acid pH in the treatment of some UIT disorders.

Review Questions

Very Short Answer Questions

Question. 1. Define Acidifying agents?
Answer. Acidifying agents are the inorganic chemical substances that either produce or increase acid in the g.i.t. tract.

Question 2. Write down the classification of Acidifying agents?
Answer. Acidifying agents can be broadly classified as :-

  1. Gastric acidifier
  2. Urinary acidifier
  3. Systemic acidifier
  4. Acids

Question 3. What is the difference between Urinary Acidifier and Systemic Acidifier?
Answer. Urinary Acidifiers are the drugs which are used to remove acidic urine from the body or to maintain the pH of the urine while Systemic Acidifiers are the drugs which are able to neutralise the alkaline body fluids especially blood.

Question 4. What do you understand by Systemic Acidifiers?
Answer. Systemic Acidifiers are the drugs which are able to neutralise the alkaline body fluids especially blood.

Question 5. By which other names Hydrochloric acid is also known?
Answer. Spirit of salt, Muriatic acid

Question 6. How would you prepare Hydrochloric acid?
Answer. Hydrochloric acid can be prepared by the action of cone. Sulphuric Acid on Sodium Chloride and passing the librated Hydrogen Chloride through water.

NaCl + H2SO4—————–>NaHSO4+ HCl

Question.7. What is Achlorhydria?
Answer. Achlorhydria is the absence or insufficient quantity of HC1 acid in the gastric secretion.

Question.8. What are the pharmaceutical uses of Hydrochloric Add?
Answer. Hydrochloric Acid is used as a pharmaceutical aid, as acidifying agent or acidifier.

Fill In The Blanks

1. Acidifying agents are the inorganic chemical compounds that either………… in the g.i.t. tract.

Answer: Produce or increase acid

2. Gastric acidifier are the drugs which are used to……………..the acidity of the stomach.

Answer: Increase

3……………….are the drugs which are used to remove acidic urine from the body or to maintain the pH of the urine.

Answer: Urinary acidifer

4……………….are the drugs which are able to neutralise the alkaline body fluids.

Answer: Systemic acidifier

5. Hydrochloric acid is also known as………………

Answer: Spirit of salt, Muriatic acid

6. Hydrochloric acid can be prepared by the action of…………………on…………………….

Answer: Cone, sulphuric acid, Sodium chloride

Antacids

Antacids are the substances which are used to neutralise the gastric acidity. Antacids occur due to excessive secretion of HC1 in stomach due to various reasons. They produce sympathomimetic relief from pain, heart burns or by neutralizing the excess of hydrochloric acid.

Peptic ulcers occur due to defective oesophageal sphincter as hiatal hernia. Gastric ulcers occur in lesser curvature and are found in first portion of duodenum.

The neutralizing capacity of an antacid is expressed in milliequivalents (mEq) of hydrochloric acid. Every antacid may have a total neutralizing capacity of atleast 5 mEq of HCl per
dosage unit.

Antacids raise the pH of the gastric contents to above 3.5.

Antacids may be classified as

  1. Systemic (absorable) antacids: These are soluble, readily absorable and capable of producing systemic electrolytic alterations and alkalosis. Example: Sodium Bicarboante.
  2. Non-systemic (Non-absorable) antacids: These are not absorbed to a significant extent and thus do not exert an appreciable systemic effects e.g. Aluminium salts, Magnesium
    salts and Calcium Carbonate.

Ideal Characteristics of Antacids :

  1. The antacid should not be absorbable or cause systemic alkalosis.
  2. The antacid should not be a laxative or cause constipation.
  3. The antacid should exert its effect rapidly and over a long period of time.
  4. The antacid should probably inhibit pepsin.
  5. The antacid should have buffer in the pH range of 4-6.
  6. The reaction of the antacid with gastric hydrochloric acid should not cause a large evolution of the acid.

Sodium Bicarbonate

Molecular formula: NaHCO3                Molecular Weight: 84.01

Synonyms

Sodium Hydrogen Carbonate, Baking Soda, Mitha Soda.

It is highly water-soluble antacid with a very rapid onset of action but relatively short duration.

Preparations

On small scale, it is prepared by passing C02 gas through a solution of sodium hydroxide.

SODIUM BICARBONATE

Solvay Process (Ammonia Soda Process)

Strong solution of Sodium Chloride containing a high concentration of ammonia is passed thorugh a carbonating tower where it is saturated with CO2 gas under pressure.

Solvay Process (Ammonia Soda Process)

Ammonia and Carbon Dioxide react to form Ammonium Bicarbonate which further undergo decomposition to form Sodium Bicarbonate.

It is specific in the treatment of systemic acidosis.

Official test for identity.

  1. Gives the reaction characteristic of sodium and of bicarbonate.
  2. To a solution of the substance in C02 free water, phenophthalein solution is added. A pale link is produced.

Physical Properties

  1. It occurs as white crystalline or amorphous powder.
  2. It is having a saline taste.
  3. Its solution is alkaline in nature.
  4. Its freely soluble with water but practically insoluble in alcohol.

Assay

Weigh accurately about 0.6gm of sodium carbonate, previously dried, dissolved in 50 ml of water and titrate with 0.5 ml/HCl acid (Indicator : 3 drops of bromophenol blue TS).

Test for Purity

Test for alkalinity, aluminium, calcium, insoluble matter, arsenic, iron, lead, chloride, sulphate, ammonium compounds.

Uses

It is mainly used as an Electrolyte Replenisher. It is mainly used for its Acid Neutralizing properties. It is also find used as an antacid. It is used as local applicant for bums, insect bites etc.

Aluminium Hydroxide Gel

Chemical formula : Al(OH)3 Molecular Weight: 77.99

Synonym

Aluminium Hydroxide Powder, Aluminium Hydrated Powder
It can be recognized into two ways

  • Aluminium Hydroxide Gel
  • Dried Aluminium Hydroxide Gel

Aluminium Hydroxide Gel :

It is a white viscous suspension of Hydrated Aluminium Oxide with varying amounts of basic Aluminium Carbonate. It gets separated into the clear liquid on standing for sometime.
It exhibits suitable flavouring and antimicrobial agent. It has a pH between 5.5 and 8.0.

Preparation

When an Aluminium Salt such as Aluminium Chloride is treated with Ammonia or Sodium Carbonate, a white gelatinous precipitate of aluminium hydroxide is obtained.

ALUMINIUM HYDROXIDE GEL

After complete removal of CO2, the precipitate Aluminium Hydroxide is filtered, washed throughly with hot water untill it become free from sulphates ions. The precipitate may be
suspended in the purified water to strengthen aluminium hydroxide gel.

Dried Aluminium Hydroxide Gel

Synonyms

Aluminium Hydroxide powder.

Properties

It is not a typical gel but is a white, odorless, tasteless, amorphous powder. It is insoluble in water and alcohol but soluble in dilute mineral acids & solution of fixed Alkali Hydroxides.

It forms gel on prolonged contact with water. It absorbs certain acids and CO2 It has a pH between 5.5-8.0

One major drawback of gel is that of a loss of antacid properties on aging.

Test for purity

Tests for arsenic, ammonium salts, chloride, lead, sulphate, alkalinity neutralising capacity, viscosity. The presence of ammonium salt is determined by heating the substance with Sodium Hydroxide to yield Ammonia which is collected in standard acid and back titrated by the usual procedure.

The limit of Ammonia in Aluminium Hydroxide is determined to be 0.034%. An aqueous solution after addition of HQ acid complies with the limit test for Chlorides. Neutralising capacity is found by measuring pH suspension of the substance in a radium which is approximate N/20 in resp. of HQ acid.

Storage

It should not be stored at a temperature not exceeding 25°C and should be stored in air tight containers.

Calcium Carbonate

Chemical Formula: CaC03           Molecular Weight: 100.09

Synonyms

Precipitated Chalk, Precipitated Calcium Carbonate. It is found in nature as the lime stone, marble calcite, vaterite, aragonite and shell of sea animals.

Method of Preparation

It can be prepared by mixing the boiling solutions of Calcium Chloride and Sodium Carbonate and allowing the resulting precipitate to subside on cooling.

CALCIUM CARBONATE

Properties

It occurs as a white, odorless, tasteless, microcrystalline powder. It is practically insoluble in air but solubility is increased by the presence of Carbon Dioxide and also by Ammonium
salts (except Ammonium Carbonate).

It is stable in air. It exists in two crystal form and both are of commerical importance, one Aragonite and other is Calcite.

Uses

It is used as fast-acting antacid, in calcium deficiency, dentrifices and in combination with magnesium containing antacids due to its constipative properties.

Magnesium Hydroxide

Synonyms: Milk of magnesia

Molecular formula: Mg(OH) Molecular weight: 58.31

Molecular weight: 58.31

Preparation

It is prepared by Combining a solution of many magnesium salts with basic water induces precipitation of solid Mg(OH)2:

MAGNESIUM HYDROXIDE

On a commercial scale, Mg(OH)2 is prepared by treating seawater with lime Ca(OH)2.

MAGNESIUM HYDROXIDE

Properties

It occurs as white, odourless powder. It is soluble in dilute acids and practically insoluble in ethanol and water.

Uses

It is used as a laxative to relieve constipation.
It is also used to treat gastrointestinal ailments such as heartburn, general upset stomach, or feelings of indigestion.

 

Review Questions

Very Short Answer Questions

Question. 1. Define Antacids?
Answer. Antacids are the drugs which are used to neutralize the gastric contents.

Question.2. How do antacids occur?
Answer. Antacids occur due to excessive secretion of hydrochloric acid in stomach.

Question.3. Classify Antacids?
Answer. Antacids can be classified into two categories :

  1. Systemic antacids
  2. Non-systemic antacids

Question.4. What is Systemic Antacid?
Answer. Systemic Antacid is readily absorable and capable of producing systemic electrolytic alterations and alkalosis. For example: Sodium bicarbonate

Question.5. What is Non-Systemic Antacid?
Answer. Non-systemic Acid is absorbed to a significant extent and thus do not exert an appreciable systemic effects.
For example : Aluminium salts such as Aluminium hydroxide gel, Calcium Carbonate.

Question.6. What do you understand by Neutralizing Capacity?
Answer. The Neutralizing Capacity of an antacid is expressed in milliequivalents (mEq) of hydrochloric acid.

Question.7. Enlist various inorganic compounds which are used as an Antacids?
Answer. Aluminium Hydroxide, Sodium Bicarbonatem Magnesium Oxide, Calcium Carbonate.

Question.8. What is the chemical formula for

  1. Sodium bicarbonate
  2. Calcium carbonate

Answer.

  1. NaHC02
  2. CaCO3

Question.9. By which other names Magnesium Oxide is known?
Answer. Magnesia.

Question.10. How would you prepare Magnesium Carbonate?
Answer. Magnesium Carbonate is prepared by mixing hot solution of Magnesium Sulphate and Sodium Carbonate. The precipitate is collected and washed with water and then
dried.

Question.11. What are the Pharmaceutical uses of Sodium Bicarbonate?
Answer. Sodium Bicarbonate is used as fast acting antacid in dentrifices. It is used as a local applicant for bums, insect bites etc.

Question.12. How would you prepare Sodium Bicarbonate?
Answer. Sodium Bicarbonate can be prepared by mixing the hot solution of Calcium Chloride and Sodium Carbonate and allowing the resulting precipitate to subside on cooling.

SODIUM BICARBONATE

Question.13. How would you prepare Magnesium Oxide?
Answer. Magnesium Oxide can be prepared by heating gently Magnesium Carbonate on redness.

Magnesium Oxide

Question.14. What are the ideal characteristics of an Antacids?
Answer.

  1. Antacid should be absorable or cause systemic alkalosis.
  2.  Antacid should probably inhibit pepsin.
  3. It should exert its effect rapidly and over a long period of time.

Fill In The Blanks

1. Antacids are the drugs which are able to……………..

Answer: Neutralize the gastric contents

2. Systemic antacid is…………….in nature while non-systemic antacid is ……………….

Answer:Absorbable, non-absorable

3. Example of systemic antacid is……………

Answer: Sodium Bicarbonate

4. Neutralizing capacity of an antacid is expressed in…………….

Answer: Milliequivalents of hydrochloric acid

5. Magnesium oxide can be prepared by heating………….on redness.

Answer: Magnesium Carbonate

6. Sodium bicarbonate is used as……………………

Answer: Dentrifice, in Calcium deficiency

7……………………..are the inorganic compounds which are used as Antacids.

Answer: Magnesium Carbonate

8. Magnesium oxide is also known as………………….

Answer: Magnesia

9. Magnesium carbonate is prepared by mixing ……………and……………….

Answer: Magnesium Sulphate, Sodium Carbonate

10………..is the aluminium containing salt as antacids.

Answer: Aluminium hydroxide gel.

Saline Cathartics

Cathartics waif he defined as those drugs which are used to bring about defecation i.e. emptying of the stomach.

Cathartics are used to

  1. To relieve from acute constipation.
  2. To ease in daefecation of patients suffering from harmful haemorrhoids or other rectal disorders.
  3. To clear bowels from stomach before surgery.

Laxatives are mild Carthatics while Purgatives are used for strong Carthatics. They act both by retaining fluids in the bowel. They should not be used on a regular basis because
they can cause water and electrolyte imbalance.

Stimulants, Bulk-forming, Emollients and Saline carthatics are the four types of laxatives. They may be administrated either by oral route (such as suspension or powder) or by rectal route (such as enema or suppository).

Inorganic compounds such as Sodium Potassium Tartarte and Magnesium Sulphate as widely used as Saline Carthatics

Classification

Laxatives can be conveniently classified into five categories :

Stimulant Laxatives: These act on the intestinal tract to increase its motor activity e.g. phenolphthalein, castor oil.

Saline Laxative: A number of magnesium salt as well as sulphate, phosphate and tartartes are used as saline laxative/carthatic. These cations and anions are not absorbed or slightly absorbed from the gastro intestinal tract.

Bulk-forming laxatives: These include natural and semisynthetic polysaccharides and cellular derivatives that are only partially digested. The undigested portion is hydrophilic & swells in presence of water to orm viscous gel.

Lubricant laxatives: These drugs (mineral oil & vegetable oil) lubricate the intestinal tract, soften the faecal contents & lubricate the passage of faeces.

Pecal softeners: Substance in this category are wetting agents e.g. docusate sodium which are non-absorbable & relatively non-toxic.

Mode of action: The saline carthatics act by increasing the osmotic load of GIT. These carthatics are salts of poorly soluble anions and cations. The body relieves hypertonidty off
the gut by secreting additional fluid into the intestinal tract.

This result is increased bulk in GIT. The resulting increasing bulk stimulates peristalsis. The saline carthatics are water soluble
and are taken with large amounts of water.

Magnesium Sulphate

Molecular Formula: MgS04.7H20                         Molecular Weight: 246.5

Synonyms: Epsom salt, Magnesium sulphate

Method of Preparation

It is obtained by the action of dilute Sulphuric Acid on Magnesium Carbonate or Magnesium Oxide. The solution obtained is filtered off and then evaporated to crystallisation.

MAGNESIUM SULPHATEProperties

It occurs as odourless, brillant, colourless crystals or white crystalline powder. It is having a bitter saline and cooling taste. It efflorescenes in warm dry air. It is soluble in water and
sparingly soluble in alcohol. When gently heated, it readily loses its water of hydration and is converted to monohydrate which quickly becomes anhydrous to 200°C.

Assay

This is a volumetric method and a complexometric assay. It is assayed by the titration of the substance against M/20 sodium edetate (disodium salt of ethylene diaminetetraacetic acid) using mordant black mixture, as indicator.

A mixture of strong ammonia and ammonium chloride is used as the buffer. The end point is the appearance of blue colour.

Storage
It should be stored in a well closed container because of its efflorescent nature.

Uses
It.acts as a saline laxative. It is also used in the treatment of magnesium deficiency, cholecystis (inflammation of gall bladder), hypertension and boils.

Sodium Orthophosphate

Molecular formula: Na2HPO4.12H20                   Molecular Weight: 358.14

Synonyms: Phosphor soda

Method of Preparation

1. It is prepared by reaction of Orthophosphoric Acid with Sodium Hydroxide.

SODIUM ORTHOPHOSPHATE

2. From bone ashes or mineral phosphorite, which is then treated with Sulphuric Acid.

Properties

It is colourless odorless, and crystalline powder. It is efflorescent. It is soluble in water and practically insoluble in alcohol.

Uses

It is used as a Pharmaceutical Aid and as a Saline Carthatic. It is used as a Buffering Agent.

Bentonite

Chemical Formula: Al2O3.4SiO2.H2O

Synonyms: Clay

It is a natural, colloidal, and an absorbent aluminium phyllosilicate consisting mostly of montmorillonite, Al2O3.4SiO2.H2O. It may also contain magnesium, calcium and iron. Volclay bentonite is its most common type composed of about 90% montmorillonite [Al2Si4O10(0H)2.nH20]. Other components such as feldspar [K20.Al2O3.6SiO2] and aluminosilicate containing Al2O3 , CaO, SiO2, MgO and soma K and Na.

Properties

It occurs as very fine odourless, cream coloured to greyish powder white. It is slightly earthy in taste. It is insoluble in water but soluble in organic solvents. It is stored in tightly closed containers

Uses
It is used as filler in pharmaceuticals, and due to its absorption/adsorption functions, it allows paste formation. It is also used as suspending agent.

Kaolin

Al2O3.2Si02.2H2O

Kaolin (China clay) is purified, natural, hydrated aluminium silicate of variable composition. It is derived from the decomposition of feld spar of granitic rocks. Kaolin consists of aluminium silicate with traces of compound of magnesium, calcium & iron.

Preparation

Kaolin is prepared when rock is mined, exacavated and the impurities are washed with water and then powdered. The rock is elutriated with water and large-sized particles separated. The turbid liquid is allowed to settle, heavy Kaolin containing the large particles & colloidal Kaolin containing particles of small size are separated & dried.

Properties

Kaolin has an earthy or clay-like taste. Its colour may be tinged grey, yellow brown, blue or red due to impurities. It is unctuous & soapy to touch. It is not affected by dil. HC1 or HNO3 acid but is decomposed by the prolonged boiling or treatment with cone. H2S04.

Heavy Kaolin

It is purified natural form of variable composition. Its particles are 20 pm in diameter, flat 7 irregularly arranged. With water plastic-like form is obtained which is less sticky. It is fine white or greyish-white earthy mass or powdder.

It is practically insoluble in water & in organic solvents. When the aqueous suspension is kept for sometime, the whole Kaolin settles below leaving clear supernatant liquid.

Light Kaolin

It is a native form, freed from most of its impurities by elutriation & dried. It contains a suitable dispensing agent. The particles are small, less than 2pm in diameter & have various
shape 4 size. Natural light Kaolin is a Kaolin which does not contain a dispensing agent.

Uses :

  1. Kaolins are adsorbent, anti-diarrhoeal and when given by mouth.
  2. Light Kaolin is used as a dusting powder food additive.
  3. They are employed in the sympathomatic treatment of diarrhoea & to coat irritated intestinal mucosa in case of diarrhoea.

Activated Charcoal

It is obtained from burning of organic material and as a residue during destructive distillation of various organic matter. The coarse material is crushed & powdered.

Alternatively, raw vegetable material may be treated with a solution of Zinc Chloride and Phosphoric acid and ignited to get the activated charcoal. The inorganic matter is removed by washing.

Properties

It is a fine black, odourless and tasteless powder having smooth touch & free from gritry particles. The fine powder provides more surface area for adsorbent properties.

Uses
It is a general typee of adsorbent which finds use in poisoningg. It also finds use in diarrhoea to absorb toxins.

Review Questions

Very Short Answer Questions

Question. 1. Define Cathartics.
Answer. Carthatics may be defined as those drugs which bring about defecation emptying of the stomach.

Question.2. Define Laxatives.
Answer. Laxatives are defined as those drugs which are used as mild carthatics.

Question.3. What is Purgative?
Answer. Purgative is defined as those drug which is used as a strong carthatic.

Question.4. Enlist various inorganic compounds which are widely used as Laxative or Purgative?
Answer. Manesium sulphate, sodium potassium tartarte.

Question.5. How do Laxative and Purgative act?
Answer. Laxative and Purgative act by retaining fluid in the bowel.

Question.6. How many types of laxatives are there?
Answer. There are four types of laxative

  1. Stimulant
  2. Bulk-forming
  3. Emollient
  4. Saline carthatics

Question.7. What is the chemical formula of Magnesium Sulphate?
Answer. MgSO4.7H2O

Question 8. What is the method of preparation of Magnesium Sulphate?
Answer. It is prepared by the action of dilute Sulphuric Acid on Magnesium Carbonate or Magnesium Oxide.The solution obtained is filtered off and then evaporatedto crystallise it.

MAGNESIUM SULPHATE

Question.9. What are the side effects of Magnesium Sulphate when consumed in excessive amount?
Answer. Excessive use of Magnesium Sulphate causes hypermagnesaemia, gastro-intestinal irritation and watery diarrhoea.

Question.10. What is the molecular weight and molecular formula for Sodium Potassium Tartarte?
Answer. Chemical formula for Sodium Potassium Tartarte is C4H4KNa06.4H20 while molecular weight is 283.23.

Question.11. What are the other names for Sodium Potassium Tartrate?
Answer.

Potassium sodium tartarte.
Rochelle salt, Seignette’s salt

Question.12. How would you prepare Sodium Potassium Tartrate?
Answer. It is prepared by reaction of boiling solution of Potassium Bitartarte with Sodium Carbonate for sometime. The solution obtained is filtered, concentrated and crystallized.

Sodium Potassium Tartrate

Fill In The Blanks

1. ………..are used to bring about defecation.

Answer: Carthatics

2. Carthatics are used to………..

Answer: To relieve constipation

3. Laxatives are………… carthatics while Purgatives are………….. carthatics.

Answer: Mild, strong

4. Other names for Sodium Potassium Tartarte are…………..

Answer: Rochelle salt, Seignette’s salt

5 Chemical formula for Sodium Potassium Tartarte is……………..

Answer: C4H4KNa06.4H20

6. ……………… Inorganic compounds are used as saline carthatics.

Answer: Magnesium Sulphate;Sodium Potassium Tartarte

7. Excessive used of Magnesium Sulphate as saline Carthatics causes………………

Answer: G.i.t irritation and waking diarrhoea

8. Epsom salt is………………….

Answer: Magnesium sulphate

9……………………..is obtained by action of dilute Sulphuric Acid on Magnesium Carbonate.

Answer: Magnesium sulphate

10……………..is used as food additives in the preparation of meat & in cheese industry.

Answer: Sodium Potassium Tartarte

Expectorants And Emetics Notes

Expectorants And Emetics Introduction

Cough, a protective reflux (both voluntary and involuntary) helps to expel irritant matter from the respiratory tract. When a person coughs there is a short intake of breath and the larynx closes momentarily.

It is a vital part of the defence mechanism. It can be caused by infections, chemical irritants, asthma, lung tumour, breathing in dust particles. It is of two types

Productive Cough: A productive cough produces a phlegm or mucus (sputum). The mucus may have drained down the back of throat from the nose or from the lungs. A protective cough should not be supressed. It clears mucus from the lungs.

Irritative or Non-productive cough: A non-productive cough does not produce sputum. A dry, hacking cough may develop towards the end of a cold or after exposure to an irritant such as dust and smoke.

Expectorant

The latin word ‘Expectorate’ means ‘to drive from the chest’. Expectorants are drugs used to help in the removal i.e. explusion of secretions or exudate from the trachea, bronchii or lungs. Hence, they are used in the treatment of cough. They act upon the respiratory tract in two ways

By decreasing the viscosity of the bronchial secretion and facilitating their elimination;local irritants are expelled and ineffectual coughing is required.

By increasing the amount of respiratory tract fluid, a demulcent action is exerted on dry mucosal lining & relieving the unproductive cough.

Inorganic saline expectorants are:- Ammonium salts (Ammonium Chloride), iodide (Potassium/Sodium Iodide), citrates and Antimony Potassium Citrate.

Read and Learn More Pharmaceutical Inorganic Chemistry Notes

Potassium Iodide

Chemical Formula: KI                 Molecular Weight:166.01

Synonyms: Kalii Iodidum, Pot. Iod.

Method of Preparation

It is prepared by treating iron filling with iodine under water to get iodide which is then reacted with potassium carbonate.

POTASSIUM IODIDE

Hydroiodic acid when treated with potassium bicarbonate results in the formation of potassium iodide.

POTASSIUM IODIDE

Properties

It occurs as odourless, transparent or opaque crystals. It is white granular powder. It is slightly hygroscopic, taste is saline and slightly bitter.

It is very soluble in water and even more so in boiling water, freely soluble in glycerine and soluble in alcohol. On long exposure to air it becomes yellow due to liberation of iodine and small quantity of iodate may be formed.

Iodine readily dissolves in an aqueous solution of potassium iodide, forming a dark brown solution which contains potassium iodide.

POTASSIUM IODIDE

Uses

It is used as an ingredient of expectorant mixture. It may be used for the prophylaxis and treatment of simple goitre. It is used as an antifungal agent in veterinary practise. Potassium
iodide solution is used as iodine supplement.

Ammonium Chloride

Chemical Formula: NH4Cl                 Molecular Weight: 53.49

Synonyms:

Ammonium Muriate, Sal Ammoniac, Salmiac, Amchlor, Ammon. Chlor.

Ammonium chloride occurs naturally in volcanic regions, forming on volcanic rocks near fume releasing vents.

Method of Preparation

It is a product of the Solvay Process used to produce Ammonium Chloride and Sodium Carbonate.

AMMONIUM CHLORIDE

This method is used to minimize ammonia release in some industrial operations. Ammonium chloride is prepared by combining ammonia with either hydrogen chloride (gas)
or hydrochloric acid.

AMMONIUM CHLORIDE

Properties

It is a white crystalline salt, highly soluble in water. Solutions of ammonium chloride are mildly acidic. It is somewhat hygroscopic. It is odourless and possesses cooling saline taste.
On heating, it sublimes without melting.

Ammonium chloride reacts with a strong base e.g. sodium hydroxide to release ammonia gas.

AMMONIUM CHLORIDE

Ammonium chloride also reacts with alkali metal carbonates at elevated temperatures, giving ammonia and alkali metal chloride.

AMMONIUM CHLORIDE

Storage

It should be stored in tightly closed containers because it is hygroscopic.

Assay

A modified Volhard’s method was used in I.P. 66. A solution of the substance acidified with nitric acid, is shaken with a measured yohjme of N/10 AgNP3, nitrobenzene being previously added.

Nitrobenzene is added to coagulate the precipitiate of AgCl, so that it will not interfere with the titrated later of excess of AgNO4 which is determined by titratio with N/10 ammonium thiocyanate, using ferrric ammonium sulphate as indicator.

AMMONIUM CHLORIDE

The following is the reaction taking place at the end point when red ferric thiocyanate is formed.

ferric thiocyanate

Uses

Ammonium chloride is a nitrogen source in fertilizers e.g. chloro ammonium phosphate. It is used as an expectorant in cough medicine. Its expectorant action is caused by irritative action on the bronchial mucosa.

Ammonium chloride is used as a systemic acidifying agent in treatment of severe metabolic alkalosis. It is also used as an flavouring agent It is used in the textile and leather industry in dyeing, tanning, textile printing and to luster cotton. It is used in hair shampoos as a thickening agent.

Emetics

An emetic is a drug that produces vomiting. Vomiting is the involuntary, forceful expulsion of the content of one’s stomach and sometimes the nose. Emetics act either directly or by stimulation of the chemeoreceptor trigger zone in the floor of IV th ventricle in medulla or reflexly by irritant action on gastro-intestinal tract.

It is used medically where a substance has been ingested and must be expelled from the body immediately. Gastric secretions and likewise, vomiting are highly acidic. Salt water and mustard water have been used since ancient times as emetic Hydrogen peroxide is used as an emetic in veterinary practise Inorganic compounds e.g.

Copper sulphate, Sodium chloride, Zinc sulphate and Potassium antimony tartarte belong to the latter type. Emetics should be avoided in children and in the elderly pregnant women and in patients suffering from CNS depression, unconscious or in coma.

If the vomiting reflex continues for an extended period, dehydration, hypokalaemia and alkalosis may occur and replacement of fluid and electrolytes may be necessary. Emetics are also sometimes used in the preparation of cough syrups.

Copper Sulphate

Synonym: Blue vitriol

Chemical Formula: CuSO4.5H2O

Molecular Weight: 159.6

Preparation:

It is prepared by dissolving cupric oxide (or) cupric hydroxide (or) cupric carbonate in dilute H2SO4.

COPPER SULPHATE

Properties

Its hydrated salt is blue in colour but anhydrous salt is colourless. It readily dissolves in water but is insoluble in alcohol.

Uses

It is used as a germicide and insecticide in agriculture. A mixture of copper sulphate and lime, commonly known as Bordeaux mixture, is used as fungicide. It is used in electroplating, calico printing and in electrical batteries.

Assay:

Weigh accurately 1 gm of copper sulphate (CuS04) in 50 ml of water, add 3 gm of potassium iodide, 5 ml of acetic acid and titrate the liberated iodine with 0.1 N Sodium thiosulfate (Na2S2O3) using solution of starch as indicator.

Sodium Potassium Tartrate

Synonyms: Rochelle salt

Chemical Formula: C4H4NaKO6

Molecular Weight: 210.158

Properties

It occurs as colourless crystals, saline in taste, soluble in hot water and insoluble in alcohol.

Uses:

It is used as laxative. It has also been used1in the process of silvering mirrors.

Expectorants And Emetics Very Short Answer Questions

Question.1 What do you understand by the term ‘Cough’?
Answer: Cough, a protective reflux (both voluntary and involuntary) helps to expel irritant matter from the respiratory tract.

Question.2 How many types of cough are there?
Answer: There are two types of cough :
1) Productive cough
2) Non-productive cough/Irritant cough

Question.3 Define Expectorants?
Answer: Expectorants are drugs used to help in the removal or explusion of secretions or exudate from the trachea, bronchii or lungs.

Question.4 Name any two inorganic compounds which are used as Expectorants?
Answer: 1) Ammonium salts such as Ammonium chloride
2) Iodide such as Potassium Iodide.

Question.5 How do expectorants act upon the respiratory tract?
Answer: Expectorants act upon the respiratory tract in two ways :

  1. By decreasing the viscosity of the bronchial secretion and facilitating their elimination; local irritants are expelled and ineffectual coughing is required.
  2. By increasing the amount of respiratory tract fluid, a demulcent action is exerted on dry mucosal lining and relieving the unproductive cough.

Question .6. What is the difference between emetic and vomiting?
Answer. An emetic is a drug that produces vomiting while vomiting is the involuntary; forceful expulsion of the contents of one stomach and sometimes the nose.

Question.7. Name two inorganic compounds which are used as emetics?
Answer. Copper sulphate, Zinc sulphate
Sodium chloride Potassium antimony tartrate

Question.8. What is the molecular formula of antimony potassium tartarte?
Answer. Molecular formula of antimony tartarte is C4H4O7SbK.1/2H2O.

Question.9. Which inorganic compound is used in the prevention and treatment of goitre?
Answer. Potassium iodide.

Question.10. What is the difference between productive cough and non-productive cough?
Answer. Productive cough produces a phlegm or mucus (sputum) while non-productive cough does produce sputum.

Question.11. How do emetics act?
Answer. Emetics act either directly or by stimulation of the chemeoreceptor trigger zone in the floor of IVth ventricle in medulla or refluxly by irritant action on gastro intestinal tract.

Question.12. What is the method of preparation of Ammonium Chloride?
Answer. Ammonium chloride is prepared by reacting ammonium with sodium chloride

preparation of Ammonium Chloride

Question.13. Which expectorant is prepared by Solvay process?
Answer. Ammonium chloride.

Question.14. What is the other name of Kali Iodidum?
Answer. Kali iodidum is also known as Potassium Iodide.

Question.15. What is the structural formula of Antimony Potassium Tartrate?
Answer. Structural formula of Antimony potassium tartrate is

Structural formula of Antimony potassium tartrate is

Question.16. What is the othei name of Antimony Potassium Tartrate?
Answer.

  1. Tartarised antimony
  2. Potassium antimonyl tartrate

Question.17. What are the Pharmaceutical uses of Potassium Iodide?
Answer: Potassium iodide is used as an ingredient of expectorant mixture. It is also used as an Iodine supplement.

Expectorants And Emetics Fill In The Blanks

1. Cough is a……………. reflux.

Answer: Protective

2. Emetics are used to produce…………………………..

Answer: Vomiting

3. Ammonium chloride is prepared by…………………

Answer: Solvay process

4. The latin word ‘expectorate’ means …………………….

Answer: To drive from the chest

5. Productive cough produces a…………………..

Answer: Mucus

6. Expectorants are used to help in the…………………

Answer: Removal of secretions

7. ………………….inorganic compound are used as saline expectorants.

Answer: Potassium iodide/ammonium chloride

8. Ammonium chloride is also known as ‘………………………

Answer: Ammonium Muriate/Amchlor

9. Antimony potassium tartarte is also known as…………………….

Answer: Emetic tartarte/Tartarised antimony

10………………….is used as an emetic in verterinary practise.

Answer: Hydrogen Peroxide

11………………….is used as emetic in ancient times.

Answer: Salt water/Mustard water

12. Solutions of ammonium chloride is highly…………..

Answer: Acidic

13. Ammonium chloride is………………in nature.

Answer: Hygroscopic

14. Potassium iodide is prepared by treating……… with………….under water.

Answer: Iron fillings with iodine

15. Ammonium chloride is used as………………in fertilizers.

Answer: Nitrogen source

Expectorants And Emetics Multiple Choice Questions

1. Productive cough produces.

  1. Mucus
  2. Vomiting
  3. Amalgam
  4. None of these

Answer: Mucus

2. Which cough does not produce mucus?

  1. Productive cough
  2. Both a) and c)
  3. Non-productive cough
  4. None of these

Answer: Non-productive cough

3. Which inorganic compound is used as Emetic?

  1. Ammonium chloride
  2. Potassium antimony tartarte
  3. Potassium iodide
  4. Potassium citrate

Answer: Potassium iodide

4. ‘KI’ stands for

  1. Potassium iodide
  2. Potassium iodate
  3. Potassium citrate
  4. None of these

Answer: Potassium iodide

5. Emetics act

  1. By stimulation of the chemeoreceptor trigger zone
  2. By increasing the amount of fluid
  3. By decreasing the viscosity of the bronchial secretion
  4. None of these

Answer: By stimulation of the chemeoreceptor trigger zone

6. If the vomiting reflex continues for an extended period,……….occurs.

  1. Dehydration
  2. Alkalosis
  3. Hypokalemia
  4. All of the above

Answer: All of the above

Antidotes in Poisoning

Antidotes Introduction

Poison may be defined as any substance that when introduced into or absorbed by a living organism causes illness or death.

Poisoning occurs in many ways

  1. by accidentally
  2. by use of recreational substances (such as cannabis, opiates etc.)
  3. by intentional behaviour
  4. by occupational exposure

So, as to counteract the effects of a poison, antidotes are used.

Antidotes

An antidote is an agent with specific action against the activity or effect of a poison.

OR

An antidote is an agent which counteracts as a poison.

Whether accidental or intentional, the poisoning requires only sympathomimetic and supportive therapy i.e. removal of poison from the body is first priority in case of poisoning.

It can be done by either gastric lavage or emesis induction (Gastric lavage is the process of cleaning the stomach) while (emesis induction can be done by the administration of substances like activated charcoal to reduce the absorption).

Classification Of Antidotes

The antidotes are classified into three types depending upon their mechanism of action.

Physiological antidotes: They act by producing the effects opposite to that of poison.

For example: Sodium nitrite which converts haemoglobin into methaemoglobin in order to bind cyanide, atropine & physostigmine.

Mechanical antidotes: These render the poison inert by mechanical action or prevent their absorption.

For example: Activated charcoal absorbs the poison to absorption across the intestinal wall, mercuric chloride, sulphanilamide.

Read and Learn More Pharmaceutical Inorganic Chemistry Notes

Chemical antidotes: They change the chemical nature of the poison.

For example:

  1. Sodium thiosulphate which changes toxic cyanide to non-toxic thiocyanate.
  2. Sodium sulphate is used to precipitate lead.
  3. Copper sulphate is used to precipitate phosphorous.

Universal antidote is a combination of physical and cheical antidote. It is an antidote which can be used in cases, where the nature of the poison swallowed is not definitely know. The universal antidote has following composition :

  1. Powdered animal charcoal
  2. Tannic acid ‘ • ‘
  3. Magnesium oxide

Antidotes Reasons Of Poisoning

Poisoning of the body is due to various reasons. It can be due to the presence of heavy metals such as lead, arsenic, mercury, and cadmium; insecticides or pesticides used in our
daily life and cyanide poisoning which occurs due to a variety of occupational sources.

Antidotes Lead Poisoning

Lead poisoning has been recognized as a major public health risk, particularly in developing countries. Though various occupational and public health measures have been under taken in order to control lead exposure.

Lead is regarded as a potent occupational toxin and its toxicological manifestations are well known. In case of severe lead poisoning, Sodium calcium edetate & dimercapol are
commonly used. Chelation therapy has so far been used.

Sodium Calcium Edetate leads from bone and the extra cellular space and then expels it out from the urine. Dimercapol is more effective than the sodium calcium edetate as chelating. It lead from the soft tissues such as brain.

Now a days, Succimer a water soluble analogue of dimercapol has been increasingly preferred. It is suitably administrated by mouth and is well tolerated.

It occurs by a number of ways such as inhalation or ingestion of soluble cyanide salts or cyanide releasing substances like seeds of peach, apricot, cyanamide, cyanogen chloride and
bitter almonds.

It has a characteristic odour of bitter almonds. The symptoms of cyanide poisoning are: Nausea, hypotension, dizziness, drowsiness, coma, convulsions and death.

Cyanide Poisoning

Cyanide poisoning takes place intentionally or accidentally to commit suicide. Two inorganic antidotes are used such as sodium nitrite and sodium thiosulphate to counteract its poisoning.

Nitrate generates ferrous ion of haemoglobin to the ferric ion of methahaemoglobin which has high affinity for cyanide radicals and form cyanomethaemoglobin. However, this
may again dissociate to release cyanide. Therefore, sodium thiosulphate is given to form sodium thiocyanate which is poorly dissociable and is excreted in the urine.

flow chart Of CYANIDE POISONING

Sodium nitrite is used for this purpose because it has a very weak vasodilator action.

Sodium Nitrite

Chemical formula: NaNO2      Molecular Weight: 69.00

Synonym: Nitrous acid Sodium salt

Preparation

It can be prepared by strongly heating sodium nitrate.

SODIUM NITRITE

It is more conventinely made by heating the sodium nitrate with metallic lead or carbon which reduces it at lower temperature.

SODIUM NITRITE

Physical Properties

  1. It is odourless, colourless to slightly yellow crystals.
  2. Its taste is saline.
  3. It is water soluble and sparingly soluble in alcohol.
  4. It is hygroscopic.
  5. It is slowly oxidizes to nitrate in air.

Chemical Properties

1. Sodium Nitrite is easily decomposed by the acidification with dilute sulphuric acid.

Chemical Properties Of SODIUM NITRITE

2. It also act as a reducing and oxiding agent.

Chemical Properties Of SODIUM NITRITE

3. With aniline hydrochloride at 4°C, Nitrous acid forms diazonium chloride.

Chemical Properties Of SODIUM NITRITE

Uses

  1. It is used in treatment of cyanide poisoning in conjugation with sodium thiosulphate.
  2. Sodium nitrate is also used as a rust inhibitor preservative in foods such as cured meals for manufacturing dyes.
  3. It is used as a vasodilator.

Sodium Thiosulphate

Chemical formula: Na2S2O3.5H20                                                     Molecular Weight: 248.2

Synonym: Sodium hyposulphate

Preparation

It can be prepared by boiling sodium sulphite with sulphur.

SODIUM THIOSULPHATE

It can be obtained by mixing sulphide liquors sodium carbonate by passing S02 gas.

SODIUM THIOSULPHATE

It is prepared by passing the sulphur dioxide gas into solution of sodium carbonate.

SODIUM THIOSULPHATE

The sodium bisulphite so obtained further reacts with sodium carbonate to give the sulphite.

SODIUM THIOSULPHATE

Physical Properties

  1. It occurs in the form of large, colourless crystals.
  2. It is odourless and is having an alkaline taste.
  3. It is soluble in water but insoluble in alcohol.
  4. It effloresces in warmy dry air above 33°C.
  5. When exposed to the moist air, it deliquesces lightly.

Chemical Properties

Sodium thiosulphate when acidified with hydrochloric acid, it decomposes to give sulphur dioxide, water and sulphur.

Thiosulphate act as reducing agent as shown by reaction with the ferric chloride solution.

Chemical properties Of SODIUM THIOSULPHATE

It is also called as antichlor in bleaching due to its reaction with chlorine or hypochlorite

Chemical properties Of SODIUM THIOSULPHATE

Assay

It is assayed by the iodemetric titration. Dissolve an accurately weighed amount of substance in water & titrate with 0.05M iodine solution using starch mucilage as indicator.

Chemical properties Of SODIUM THIOSULPHATE

End point is indicated by the presence of blue colour.

Uses

  1. It is used in the treatment of Cyanide Poisoning. It is also used to treat parasitic skin diseases.
  2. It is used as antichlor in bleaching process in textile industry.
  3. It is widely used as stimulant analytical chemical.

Antidotes Short Answer Questions

Question. 1. Differentiate between Poison and Antidote?
Answer. Poison may be defined as any substance that when introduced into or absorbed by living organism causes illness or death while an antidote is an agent which counter
act as a poison.

Question.2. Which kind of therapy is required for Poisoning?
Answer. Poisoning requires sympathomimetic and supportive therapy.

Question.3. How poisoning can be removed immediately from the body?
Answer. Poisoning can be removed immediately from the body by gastric lavage or emesis induction.

Question.4. How poisoning can be occurred?
Answer. Poisoning can occur in many ways:-

  1. by accidentally
  2. by use of recreational substances
  3. by intentional behaviour
  4. by occupational exposure

Question.5. Classify antidotes.
Answer. Antidotes can be classified into three types

  1. Physiological antidotes
  2. Mechanical antidotes
  3. Chemical antidotes

Question.6. Write down the examples of Mechanical Antidote?
Answer.

  1. Activated charcoal
  2. Magnesium sulphate
  3. Copper sulphate
  4. Sodium monohydrogen phosphate

Question.7. Which drugs are used in the treatment of lead poisoning?
Answer. Sodium calcium edetate and Dimercapol

Question.8. Which therapy is used for lead poisoning?
Answer. Chelation therapy

Question.9. Which antidote is used in the treatment of cyanide poisoning?
Answer. Sodium nitrite, Sodium thiosulphate

Question.10. Differentiate between Physiological antidotes and Mechanical antidotes.
Answer.

  • Physiological antidotes- They act by producing the effects opposite to that of poison.
  • Mechanical antidotes : They prevent the absorption of poison into body

Antidotes Fill In The Blanks

1. ………….is used to counteract the poison.

Answer: Antidote

2. Cyanide poisoning kit contains . …,………. and ………….

Answer: Amyl nitrite, Sodium nitrite & Sodium thiosulphate

3. Cyanide poisoning has a characteristic odour of ……………….

Answer: Bitter almonds

4………………….therapy is used for lead poisoning.

Answer: Chelation

5. Chemical antidote act by changing the……………..of the poison.

Answer: Chemical nature

6. Activated charcoal is used to…………… the poison.

Answer: Absorb

7…………………is the example of physiological antidote.

Answer: Sodium nitrite

8…………….is the molecular formula of sodium thiosulphate.

Answer: Na2S2O3.5H2O

Antidotes Multiple Choice Questions

1. An important antidote in the treatment of cyanide poison is:

  1. Ethanol
  2. Atropine
  3. Sodium thiosulphate
  4. Desferrioxamine

Answer: Desferrioxamine

2. In case of poisoning, activated charcoal acts to reduce absorption of the substance by

  1. Increasing osmotic pressure of the intestinal contents
  2. Shortening transit time thorugh the gut
  3. Binding to the poison molecules
  4. Stimulating the chemoreceptor trigger zone in the medulla

Answer: Binding to the poison molecules

3. When a poison is inhaled what methods you will be thinking of to manage the case?

  1. Induction of emesis
  2. Carrying out a gastric lavage
  3. Thinking of an active elimination technique
  4. Administration of an antidote
  5. Both c) and d)

Answer: Both c) and d)

4. An antidote is used

  1. To counteract the poison
  2. To enhance the poison
  3. To cause illness e.g. death
  4. To prdouce consiousness

Answer: To counteract the poison

5. Which of the following antidotes is not used in cyanide poisoning?

  1. Hydroxy cobalamine
  2. Sodium nitrite
  3. Dimercapol
  4. Sodium calcium EDTA

Answer: Hydroxycobalamine And Sodium nitrite

6. Which kind of antidote reduces the poison across the intestinal wall?

  1. Mechanical antidote
  2. Physiological antidote
  3. Chemical antidote
  4. None of the above

Answer: Mechanical antidote

7. Physiological antidotes act by:-

  1. Absorption of the poison
  2. Changing the chemical nature of the poison
  3. Producing the effects opposite to that of poison
  4. By countering the effects of poison

Answer: Producing the effects opposite to that of poison

8.”Cyanide poisoning kit” contains following:-

  1. Sodium nitrite
  2. Amyl nitrite
  3. Sodium bicarbonate
  4. Sodium thiosulphate

Answer: Sodium bicarbonate

9. How does mechanical antidote act?

  1. By producing the effects opposite to that of poison
  2. By preventing the absorption of poison into the body
  3. By changing the chemical nature of the poison
  4. By changing the physical nature of the poison

Answer: By preventing the absorption of poison into the body

10. Which one of the following is an example of Physiological Antidote?

  1. Sodium nitrite
  2. Sodium thiocyanate
  3. Activated charcoal
  4. Copper sulphate

Answer: Sodium nitrite

11. Cyanide Poisoning has a characteristic odour of

  1. Bitter almonds
  2. Wheat
  3. Lemon
  4. Caraway

Answer: Bitter almonds

12. Sodium nitrite is given in conjuction with:-

  1. Sodium bicarbonate
  2. Sodium thiosulphate
  3. Sodium calcium edetate
  4. Dimercaprol

Answer: Sodium thiosulphate

Astringent: What is it, Uses, Benefits

Astringents Introduction

Topical astringents are used to firm Up (tone) the skin.

Astringents

A substance that controls or tightens tissue, thereby alleviating conditions such as diarrhoea, haemonhages and secretions is known as astringent.

Astringent is applied to skin, mucous membrane and does not destruct the tissue. It will cause constriction of capillaries and small blood vessels. Astringent acts as protein precipitant and arrest discharge by causing shrinkage of tissue.

Zinc Oxide and Calamine are astringents used in lotions, powders and ointments to relieve from itching and choping in various forms of dermatitis. Astringent helps to reduce oiliness e.g. excessive precipitation.

Astringents have bacteriostatic properties, though they are not generally used as antiseptics. The protein-precipitation brought about by astringent is ascribed to presence of metallic ions having large charge/ radium ratio of strong electrostatic fields.

The metal would form complex with various polar groups present on the protein or enzyme. This complexation of important functional group at active site of protein or an enzyme cause a drastic change in properties of the protein.

ASTRINGENTS

Astringent are used to treat diarrhoea, and also possess deodorant properties. Astringent promote healing process.

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Alum

Alum is both a specific and a class of chemical compound. The specific compound is the Hydrated Potassium Aluminium Sulfate (potassium alum) with the formula KA1(S04)2.12H2O.

More widely, alums are double sulphate salts, with the formula AM(SO4)2.12H2O, where A is a monovalent cation such as Potassium or Ammonium and M is a trivalent metal ion such
as Aluminium or Chromium (IE).

Alums are prepared by adding a hot, concentrated solution of either Potassium or Ammonium Sulphate to a hot solution of an equimolar proportion of Aluminium Sulphate and the alums get separate out.

ALUM

Properties

Alum occurs as colourless, transparent, colourless crystals, white granules or powder. It has sweetish strongly astringent taste. Its crystals are sometimes opaque on the surface
due to formation of traces of basic salt.

It is freely soluble in water but slowly dissolves in glycerine and insoluble in alcohol. The aqueous solution is acidic to litmus.

On heating potash alum melts, it loses the water of crystallization below 200°C, forming a white residue of anhydrous aluminium sulphate and potassium sulphates. It is soluble in the water but insoluble in alcohol.

Assay

Complexometirc titration of aluminium is carried out 0.9gm is dissolved in the 20 ml of water. Each ml of 0.1N disodium edetate is equivalent to 47.44 mg of A1K.(SO4).12H2O

Official Test for Identity

  1. A solution of water gives the reactions characteristic of aluminium & sulphate.
  2. A small quantity of a solution in water is treated with sodium bicarbonate & filtered. The filterate gives the reactions of potassium.

Uses

Alum is used as an ingredient of some brands of toothpaste or powders. It is used in many subunits vaccines as a adjuvant to enhance the body’s response to immunogen. Vaccines
include hepatitis A, hepatitis B and DTAP.

It is used by pet owners to stem bleeding associated with animal injuries caused by improper nail clipping. It is used as a haemostatic agent, as mouth washes or gargles, as bladder irrigitations.

It is a powerful astringent. It is used in making lotions and douches. It has also been used as vaginal cleaning and deodrant preparations.

Zinc Sulphate

Chemical Formula:  ZnSO4.7H2O                      Molecular Weight: 287.54

Synonym : white Vitriol

Preparation

It is prepared by boiling metallic Zinc with dilute Sulphuric Acid. A slight excess of zinc metal is used and the reaction is allowed to continue untill hydrogen gas evolves out.

ZINC SULPHATE

The solution is filtered to separate unreacted Zinc, concentrated and crystallized.

It may also be prepared by the action of dilute Sulphuric acid on Zinc Oxide.

ZINC SULPHATE

Chemical Properties

1) A white precipitate Zn(OH)2 is formed when zinc sulphate reacts with NaOH. The precipitate is solubilised in excess of NaOH.

Chemical Property Of ZINC SULPHATE

Properties

It occurs as colourless, transparent crystals or crystalline powder. It is odourless. Its taste is astringent and metallic. It is very soluble in water and freely soluble in glycerin. It efflorescenes in dry air.

Assay

An aqueous solution of ZnSO2 has been acidic to litmus, due to hydrolysis of the salt and is having pH of about 5. The solution has been acid to solution of phenol red and not acid to solution of methyl orange.

Storage

Since it is efflorescent, it should be stored in tightly closed non-metallic containers.

Incompatibility

It is incompatible with alkali carbonates and hydroxides and with astringent infusions and decocations.

Uses

It is widely used as an astringent and in emetic (induces vomiting). A 0.25% aqueous solution is also used as an opthalmic astringents. It is used as reflex emetic especially in Narcotic
Poisoning (opium alkaloids poisoning). It has also been used internally as an emetic.

Astringents Short Answer Questions

Question. 1. Define Astringent.
Answer. Astringent is a substance that causes the contraction or shrinkage of tissue that dry up secretions.

Question.2. How do astringent act?
Answer. Astringent acts as protein precipitant.

Question.3. Name any two inorganic compounds that arc used as astringent?
Answer. Zinc Chloride, Alum, Zinc Sulphate.

Question.4. What Is the another name of Zinc Sulphate?
Answer. White Vitriol.

Question.5. What is the method of preparation of Zinc Sulphate?
Answer. Zinc Sulphate is prepared by the action of dilute sulphuric acid on zinc oxide.

preparation of Zinc Sulphate

Question.6. What are the pharmaceutical uses of Zinc Sulphate?
Answer. Zinc Sulphate is used as an astringent and in emesis. A 0.25% aqueous solution is also used as an opthalmic astringents.

Question.7. Write down the incompatibilities of zinc sulphate?
Answer. Zinc Sulphate is incompatible with alkali carbonates and hydroxides.

Question.8. What are the properties of Zinc Sulphate?
Answer.

  1. It occurs as colourless, transparent crystals or crystalline powder.
  2. It is very soluble in water and freely soluble in glycerine.

Question.9. Write down any two pharmaceutical uses of Alum?
Answer.

  1. Alum is used as an ingredient of some tooth paste or powders.
  2. It is a powerful astringent.
  3. It is widely used in vaginal cleansing and deodrant preparation.

Question.10. What is the taste of Alum?
Answer. It has sweetish strongly astringent taste.

Astringents Fill In The Blanks

1. An astringent is a drug which shrinks by……………………from their surfaces.

Answer: Protein precipitation

2. Commercially………..is prepared by heating metallic zinc to bright redness in the presence of preheated air.

Answer: ZnSO4

3. ………………..is used in narcotic poisoning which is also an inorganic astringent.

Answer: ZnSO4 (Zinc sulphate)

4. Astringent act as………………..

Answer: Protein precipitate

5. Astringent cause…………………of tissue.

Answer: Shrinkage or contraction

6. Alum is prepared by adding a hot cone, solution of………………. to a hot solution of…………… and it get separate out.

Answer: Ammonium sulphate, aluminium sulphate

7. ………………………..is used as astringent.

Answer: Zinc sulphate, Alum

8. Topical astringents are used to………………………..

Answer: Firm up the skin

9. Chemical formula of Alum is………………………while of Zinc Sulphate is………………

Answer: AM(SO4)2.12H2O, ZnSO4

10. ZnS04 is externally used as…………………..

Answer: Astringent

Astringents Multiple Choice Questions

1. What is the effect of astringents on tissues?

  1. Contraction
  2. Both a) and b)
  3. Shrinkage
  4. None of these

Answer: Both a) and b)

2. How do astringents act?

  1. Lipid precipitant
  2. Bacterial inhibition
  3. Protein precipitant
  4. Enzymatic catalysis

Answer: Bacterial inhibition And Protein precipitant

3. What is the chemical formula of Alum?

  1. KA1(SO4)2.12H2O
  2. K2SO4.12H2O
  3. KSO4.2H2O
  4. K(SO4)2.12H2O

Answer: KA1(SO4)2.12H2O

4. Zinc sulphate is also known as

  1. White vitriol
  2. Red vitriol
  3. Blue vitriol
  4. Yellow vitriol

Answer: White vitriol

5. Which inorganic astringent is used in the treatment of nacrotic poisoning?

  1. Alum
  2. Zinc Sulphate
  3. Aluminium chloride
  4. Zirconium Sulphate

Answer: Zinc Sulphate

6. Zinc sulphate is prepared by the action of………. on Zinc Oxide.

  1. Conc. HCl
  2. Conc. HNO3
  3. Conc. H2SO4
  4. None of these

Answer: Conc. H2SO4

Haematinics

Haematinics are substances required in the formation of blood in process of hematopoiesis and are used for treatment of anaemias. The main hematinics are B12 & folate.
These drugs increase the number of red blood cells and the amount of hemoglobin to normal level and above when they are below normal.

Anaemia occurs when the balance between production and reduction of red blood cells is disturbed

  1. Due to blood loss
  2. Impaired red cell formation due to
    1. Deficiency of essential factors: Iron, folic acid vitamin B12.
    2. Bone marrow depression, erythropoietin deficiency
  3. Increased destruction of RBCs (Haemolyticanaemia)

Ferrous Sulphate

Synonyms: Green vitriol

Molecular formula: FeSO4.7H2O

Molecular weight: 278

It contains not less than 98% and not more than 105% of FeSO4.7H2O

Preparation

When iron is treated with dilute H2SO4, iron dissolve and form ferrous sulphate and hydrogen gas is liberated.

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FERROUS SULPHATE

Ferrous sulphate Is obtained commercially by exposing the moist Iron pyrites to air when slow oxidation takes place.

FERROUS SULPHATE

Properties

Physical properties:

It occurs as transparent, pale bluish green crystalline powder; odourless; metallic in soluble in boiling water, freely soluble in water but practically insoluble in alcohol.

Chemical properties:

When it is treated with ceric ammonium sulphate [(NH4)4Ce(SO4)42 H20] in acidic medium, it reduces ceric ion.

Chemical properties FERROUS SULPHATE

Assay:

Ferrous sulphate solution may bring about discolouration of the teeth in contract. The assay is based on oxidation-reduction (redox) titration. An acidified solution of substance is titrated with ceric.

Ammonium sulphate in presence of sulphuric acid using ferrous sulphate solution as an indicator. Weigh accurately 1 gm of ferrous sulphate (FeSO4) and dissolve in 20 ml of diluted sulphuric acid in 30ml. of water. Titrate the contents of the flask with 0.1 N potassium permanganate (KMnO4) until a permanent pink colour is obtained.

Uses:

It is used as hematinic in the treatment of iron deficiency anaemia. It is also used to dye fabrics and in tanning leather.

  1. White nitric oxide, ferrous sulphate forms black colourednitroso ferrous sulphate FeSO2.NO.
  2. On heating it decomposes into ferric oxide sulphur dioxide &nelpherotrixodide.

Ferric oxide sulphur dioxide &nelpherotrixodide

Ferrous Gluconate

Molecular formula:-C12H22FeO14.2H2O                                 

Molecular weight: 482.2

FERROUS GLUCONATE

Preparation

1 . It is obtained by dissolving ferrous carbonate in calculated amount of gluconic acid. First of all gluconic acid is prepared by the oxidation of glucose.

Preparation Of FERROUS GLUCONATE

Gluconic acid is treated with BaCl2 solution which is then treated with FeS04 solution. BaS04 precipitates out & is removed by filtration.

Properties

  1. It occurs as a fine, yellowish gray & pale greenish yellow powder or granules with slight burnt sugar.
  2. It is freely but slowly soluble in water.

Assay

The assay is based on the oxidation-reduction titration. To a weighed amount (l,5gm) dissolved in water and 2N sulphuric acid, zinc powder is added & kept for 20 minutes, filtered and the filter is washed with the water.

To the combined liberate and washing ferrous sulphate solution is added & titrated with 0.1N ceric ammonium sulphate until the colour is change from orange to green. A blank determination is performed.

Use

1 . It is used for the preparation of ferrous Gluconate tablets.

Haematinics Very Short Answer Questions

Question. 1. What are haematinics?
Answer. Haematinics are substances required in the formation of blood. These drugs are used for the treatment of anaemia. These drugs increase the number of red blood cells and
the amount of haemoglobin is raised to normal level and above when they are below normal.

Haematinics Fill In The Blanks

1. Total body iron in an adult person is…………..

Answer:2.5 gm to 5 gms

2. Vitamin K] is also known as………….. is used in prevention of haemorrhagic disease of new borne.

Answer: Phytonadione

Radiopharmaceuticals

Radioactivity

The phenomenon of spontaneous emission of certain kind of invisible radiation by certain substance is called Radioactivity. The substances which emit such radiation is called

Radioactive substance. It was discovered accidentally by the French Scientist Henry Becquerel.

Radiopharmaceuticals are used in medicines. It is used to treat cancerous tumors, to diagnose thyroid disorders and other metabolic disorders including brain function.

Radioactive Rays

Radioactive radiations are composed of three important rays α, β and δ which differ very much in their nature and properties.

α-rays

These rays or particles are positively charged. It consists of two unit positive charge and has a mass which is nearly four times that of hydrogen atom. These are heavy, slow moving and their penetrtion power is slow. These rays ionise the gas through which they pass.

During the emission of a-particle from a radioactive element, atomic number decreases by 2 unit and mass number decrease by 4 units.

RADIOACTIVE RAYS

β-rays

These rays or particles are negatively charged. They have negligible mass. These having smaller mass, higher speed and thus β-particles are much more penetrting than aparticle. They have lower ionising power than α-rays.

During the emission of β-particle from a radioactive element, atomic number increases  by 1 unit and there is no change in mass number.
For example :

beta rays

γ-rays :

These rays are neutral i.e. do not carrying charge. The particle of these rays has negligible mass. As they do not have any mass, their ionising power is also very poor. They not affected by magnetic field and are having the speed of light.

Read and Learn More Pharmaceutical Inorganic Chemistry Notes

Isotopes

Atoms of an element which have the same atomic number but have different mass number are called Isotopes, in other words, isotopes are atoms of the same element whose nuclei contain the same number of protons but different number of neutrons.

When the radioactive isotopes undergo nuclear reactions and they produce α, β and γ particles. The original nuclide is called the parent and the product is termed as daughter nuclide.

This phenomenon of nuclear changes is termed as disintegration or radioactive decay.

Radioactive Decay

According to the law of Radioactive Decay, the quantity of a radioelement which disappears in unit time (rate of disintegration) is directly proportional to the amount present. It is independent of temperature, so its energy of activation is zero.

Various forms of equation for radioactive decay are

RADIOACTIVE DECAY

Where λ, is a constant, and is known as decay or disintegration constant. Integrating the equation i)

RADIOACTIVE DECAY

C is the constant of integration and log N stands for logeN. Since the number of atoms of the radioactive substance present initially i.e. t = 0 is N0

RADIOACTIVE DECAY

Substituting the value of integration constant

RADIOACTIVE DECAY

Converting log to the base e to the base 10, we get :

RADIOACTIVE DECAY

Nt= Nvunber of atoms that nucleid present after time t.

N0 = Initial number of atoms of the nucleid at time 0.

λ = Decay constant

This equation is similar to that of the first order reaction, hence it is seen that radioactive disintegration are example of first order reactions.

Units Of Radioactivity

Units of Radioactivity is Curie. Its symbol is Ci or C. It refers to the activity of one gram of radioactive material and is equal to 3.7 x1010 disintegration per second (dps).

1 Curie = 3.7 x 1010 dps

The millicurie and micro curie are equal to 10-3 or 10-6 respectively.

1 Millicurie = 3.7 x 107 dps
1 Microcurie = 3.7 x 104 dps

But nowadays, the unit curie is replaced by Rutherford (Rd).

Rutherford (Rd) is defined as the amount of a radioactive substance which undergoes 106dps.

Roentagen (R). it is the unit of exposure, 1R = 2.58 x 10-4CKg-1 (C = A Coluomb)

RAD: It is the unit of absorbed dose, 1 rad = 10-2JKg-1

However in SI system,

Bacquerel (Bq) : it is defined as one disintegration per second.

1 Bq = 1 disintegration per second

106Bq=1 rd

3.7×1010 Bq=1c

Half-Life Of Radioelement

The half-life period is defined as the time required for a radioactive isotope to decay to one half of its initial value. It is denoted by t1/2

HALF-LIFE OF RADIOELEMENT

Where λ is disintegration constant. Each radioactive isotope has its own characteristic of half-life. Shorter the half-life period of an element, greater is the number of disintegrating atoms and hence greater is its radioactivity.

The half-life periods or half lives of different radioelements vary widely ranging from fraction of seconds to millions of years.

Half-lives for various radionucleides vary considerably e.g. Polonium- 122 has half-life of 3 x10-7 seconds, uranium 238 has 4.5 x104 years.

Average Half-Life Period

The reciprocal of the radioactive constant or decay constant is called average half life period. It is denoted by Τ (tau).

AVERAGE HALF LIFE PERIOD

Example 1: Calculate the half-life period of an isotope if its disintegration constant is 1.237 x 10-4 year-1.

Solution.

half life period of an isotope

Example 2: The half-life period of a radioactive element is 2.5 days? What is the value of decay constant (λ,) in mm-1?

value of decay constant

Example 3: A radioactive substance decay at such a rate that after 46 days only 0.25 of its original amount is left. Calculate the disintegration constant and half-life period?

disintegration constant and half-life period

Measurement Of Radioactivity

To measure the radiations ofalpha, beta and gamma rays many techniques involving detection and counting of individual particles or photons have been available. It include Ionisation Chamber, Proportional counter, Geiger-Muller counter.

Ionisation chamber: An ionisation chamber consists of chamber filled with gas and fitted with two electrodes kept at different electrical potentials and a measuring device to indicate the flow of electric current.

The fill gas can be Ar, He, air etc. These available in various size and shapes. They have poor resolution due to large number of charge carriers. They are operated in current mode.

Proportional counter: If the electric field gradient between the anode & cathode is increased by increasing the applied voltage, the electrons produced in the primary ionisation further ionise the gas molecule e.g. the number of ion pair is multiplied.

For each primary electron liberated, ‘ a large number of additional electrons are liberated, the current pulse through electrical current is greatly amplified.

In a certain original number of ion pairs. Proportional counters operate in this voltage region. They are usually operated in pulse mode and are used in the form of gas filled or gas flow counters for a, b and fission frequent counting.

The most common file pass is “P-10” consisting of 90% Ar and 10% methane. The energy resolution of the proportional counter is in the range of 5-10%.

DIAGRAM OF GEIGER MULLER COUNTER

Geiger-Muller Counter: It is one of the oldest radiation detector types in existence, having been introduced by Geiger and Muller in 1928. It is referred to as G-M counter or simply tube.

The simplicity, low cost and of ease of operation of these detectors have lead to their continued use to the present time. They can detect a, P and y radiations. It consists of a cylinder made up of stainless steel or glass coated with silver on the inner side which acts as cathode.

Coaxially inside the tube a mounted fine were works as an anode. It is having the mixture of ionising gas which contain a small proportion quenching vapour.

The function of quenching vapour are i) to prevent the false pulse, ii) to absorb the photons emitted by excited atoms and molecule returning to their ground state.

Chlorine, bromine, ethyl alcohol and ethyl formate are commonly used qenching agents. Radiation when enters the tube through a thin section of outer wall causes ionisation of atoms of the gas.

When a high voltage is maintained between two electrodes, the electrons and charged ions are attracted by the anode and cathode respectively. Each particle of radiation produces a brief flow or pulse of current which can be recorded by a scalar.

Scintillation Detectors

Scintillation detectors rely on theatomic ormolecular excitation produced. Deexcitation then results in the emission of light, a process known as fluorescence.

This light then act as a detectable signal. It consists of a cell, a photomultiplier tube coupled with phosphar or flour to convert scintillations into electrical pulses, an amplifier and a scalar.

Both inorganic and organic scintillations can be used as detector. There are two main types of scintillator :

Inorganic, such as Sodium Iodide: Single crystals of Nal, doped with an activator such as Thallium to modify the energy levels which are used to form detectors.

They are insulators and have a wide gap between the valence band and conduction band suitable activators are used to create excited states which decay by emission of light in the visible range. Other scintillation like CsI (TI), CsI(Na), Hi I (Er), BaF2.

Organic Scintillator: It is used for simple α and β counting with 100% efficacy. Anthrene have high scintillation efficacy and stilbene low scintillation efficacy.
It suffer from the limitation of poor energy resolution.

MAJOR USES OF RADIOISOTOPES

Major Uses Of Radioisotopes

Storage, Handling And Precautions Of Radioactive Material

A care should be taken to protect people and personal from harmful radiation during handling and storage of radioactive material emits.

The following precautions are taken while working with radiodetectors, radio assays, traces experiments, manufacturing or handling of radioactive materials.

  1. These materials should be handled with forceps or sutiable instruments and direct contact should be avoided.
  2. Any substance which is taken internally (foods, drinks, smokes etc.) should not be carried in laboratory where radioactive materials are used.
  3. Sufficient protective clothing or shielding must be used while handling the materials.
  4. Radioactive materials should be kept in suitable labelled containers shield by lead bricks and preferably in remote corner.
  5. Areas where radioactive materials are used or stored should be monitored constantly (tested regulary for radioactivity).
  6. The final disposed of radioactive material should be done with great care to animals and environment.

Radioopque Contrast Media

Radioopaque contrast media are the chemical compounds having the capacity to absorb and block the passage of x-rays. So they are opaque to x-ray examination.

They are used as a diagnostic aid in radiology which emits x-rays. They can pass through soft tissues of the body but are observed at hard tissues (bone).

The ray produces a black spot on photographic plate by forming complex with silver bromide.

These rays does not form a bright spot of the similar shape as that of x-ray observing object is formed.

X-rays are electromagnetic radiations of short wavelength and have high penetrating power.

Radioopaque agents are typically iodine or barium compounds and are used for x-ray examinations of the kidney, liver, blood vessels, heart and brain.

Although they do not have the highest atomic numbers/they are the most easily incoorporated into molecules exhibiting low toxicity. They become concentrated in the organ to be studied.

Radiopharmaceuticals

Various radioopaque contrast media are used in the x-ray examination of gastro intestinal tract, gall bladder and bile duct, kidney and uretar, fallopian tubes, liver, blood vessels heart and brainets.

Barium Sulphate

Formula: BaSO4

Mol. Wt: 233.4

Preparation

In nature it is found as barite; also as heavy spar.

It may be prepared by adding any soluble sulphate to a soluble barium salt. For example addition of sodium sulphate to a solution of barium chloride precipitates barium sulphate.

BARIUM SULPHATE

Barium chloride on treatment with sulphuric acid causes precipitation of Barium sulphate.

BARIUM SULPHATE

Physical Properties

It is fine, heavy, white, odourless, tasteless, bulky powder free from gritty particles. It is practically insoluble in water, in organic solvents and in dilute solutions of acid and alkalies.

The bulky is free from gritty particles. It does not have any toxic effects to man and the environment.

Chemical Properties

Barium sulphate on treatment with cone, sulphuric acid results in the formation of bisulphate salt.

Chemical Properties BARIUM SULPHATE

Uses

  1. It is used as a radiopaque contrast media for the x-ray examination of the git tract.
  2. Barium ion stimulates smooth muscles causing vomiting, severe cramps, diarrhoea and haemorrhage.
  3. It is used primarily as a whitening agent and as an insoluble support in industrial applications.

Radiopharmaceuticals Short Answer Questions

Question. 1. Define Radioactivity.
Answer. The spontaneous emission of certain radiations like α, β and γ-rays is known as radioactivity.

Question.2. t1/2 of radioactive element is 100 seconds? What is the value of its disintegration constant? •

Answer:

disintegration constant

Question.3. In the sequence A→B→C→D. What is relationship between A and D?
Anwer: They are isotopes

Question.4. What is meant by rate of radioactive decay? Give general formula of decay constant?
Answer.

Rate at which radioactive element disintegrate is called rate of radioactive decay.

RADIOACTIVE DECAY

Where N0 is initial amount of radioactive substance.
Nt is final amount of radioactive substance.

Question.5. Differentiate between a, P and y rays?
Answer:

Differentiate between alpha,beta and gamma rays

Question.6. Define Curie?
Answer. It refers to the activity of one gram of radioactive material and is equal to 3.7×1010 disintegration per second. Its unit of radioactivity.
1 Curie = 3.7xl010 dps

Question.7. Define Half life? How is it denoted?
Answer. Half life period is defined as the time required for a radioactive isotope to decay to one half of its initial value.
It is denoted by t1/2.

t1/2=0.693/λ

Where λ is disintegration constant.

Question.8. Give two examples of radioisotopes?
Answer.

  1. Calcium 47
  2. Cesium 137
  3. Chromium 51
  4. Iodine 123

Question.9. What do you understand by the term Radioopaque contrast media?
Answer. Radioopaque contrast media are the chemical compounds which are having the capacity to absorb or block the passage of X-rays.

Question.10. Give two examples of Radioopaque agents?
Answer. Barium sulphate And Iodine

Question. 11 What are the uses of Radioopaque contrast media?
Answer Radioopaque contrast media are used in the x-ray examination of g.i. tract, gall bladder, bile duct, kidney and fallopian tubes.

Question.12. How is Barium sulphate prepared?
Answer. Barium sulphate can be prepared by adding any soluble sulphate to a soluble barium salt.

For example:- Addition of sodium sulphate to a solution of BaCl2 precipitates barium sulphate.

BARIUM SULPHATE

Radiopharmaceuticals Fill In The Blanks

1. Radioactivity undergo …………………..reaction.

Answer: Spontaneous

2. An alpha particle carries…………….

Answer: 2 unit positive charge

3. An beta particle is……………… charged.

Answer: Negatively

4. Isotopes have the same ………..but different……………….

Answer: Atomic number, mass number

5. The order of reaction of radioactive decay is …………………

Answer: First order

6. The t l/2 of a radioactive substance is 100 second, its X is……………………

Answer: 6.93 x lO-sec-1

7. …………………… is used for the measurement of radioactivity.

Answer: Geiger-Muller counter

8. …………………..is gas filled detector.

Answer: Ionisation chamber, proportional counter

9. The time required by given amount of the element to decay to one half of its initial value is known as…………….

Answer: Half-life

10. P-10 gas is a mixture of…………..and………….

Answer: 90% Argon & 10% methane

Radiopharmaceuticals True Or False Statement

1. Radioactive decay is first-order reaction.

Answer: True

2. Alpha particles are identical with helium nuclei.

Answer: True

3. Rate of disintegration is inversely proportional to the amount present.

Answer: False

4. (5-rays have highest penetrating power as compared to a, y rays.

Answer: False

5. Radioactivity is a spontaneous process.

Answer: True

6. Geiger-Muller counter cannot detect a, (5 and y-radiations.

Answer: False

7. Radioopaque contrast media do not need any x-ray examination.

Answer: False

Radiopharmaceuticals Multiple Choice Questions

1. Radioactivity was discovered firstly by>

  1. Henry Becquerel
  2. Rutherford
  3. J.J. Thomson
  4. Madame Curie

Answer: Henry Becquerel

2. The unit of radioactivity is:-

  1. Curie
  2. Rutherford
  3. Ohms
  4. Both a) and b)

Answer: Curie, Rutherford

3. A device used for the measurement of radioactivitv is a

  1. Mass spectrophotometer
  2. Cyclotron
  3. Nuclear reactor
  4. G.M. Counter

Answer: G.M. Counter

4. Radioactivity is due to

  1. Stable electronic configuration
  2. Unstable electronic configuration
  3. Stable nucleus
  4. Unstable nucleus

Answer: Unstable nucleus

5. When a radioactive nucleus emits an a particle, the mass number of the atom

  1. Increases and its atomic number decrease
  2. Decrease and its atomic number decrease
  3. Decrease and its atomic number increase
  4. Remain the same

Answer: Decrease and its atomic number decrease

6. Which isotope on bombardment with a-partide mil have 17/8 O and 1/1H?

C:\Users\Alekhya\Downloads\bombardment.png

Answer: b)

7. The decay of a radioactive element follows first order kinetics. As a result of:-

  1. The half life period= a constant k where k is the decay constant
  2. The rate of decay is independent of temperature
  3. The rate can be altered by changing chemical conditions
  4. None of the above

Answer: The rate of decay is independent of temperature

8. Which of the following is correct?

  1. Radioactivity is a statistical process
  2. Radioactivity is a spontaneous process
  3. Radioactivity is characteristics of some elements
  4. Both b) and c) are true

Answer: Both b) and c) are true

9. Radioactive decay is a reaction of

  1. First order
  2. Second order
  3. Third order
  4. Zero-order

Answer: First order

10. a-rays have

  1. +ve charge
  2. -ve charge
  3. no charge
  4. Sometimes +ve and sometimes -ve

Answer: +ve charge

11. Gamma rays have

  1. High penetrating power than a and P
  2. No penetrating power
  3. Less penetrating power than a and (3
  4. None of the above

Answer: High penetrating power than a and P

12. Alpha rav consists of a stream of

  1. H+
  2. He2+
  3. Only electrons
  4. Only neutrons

Answer: He2+

13. The radiation which has highest penetrating power is

  1. α-rays
  2. β-rays
  3. γ-rays
  4. None of the above

Answer: γ-rays

14. Isotopes are having

  1. Same atomic number but different mass number
  2. Same atomic number and same mass number
  3. Atomic number increases
  4. None of the above

Answer: Same atomic number but different mass number

15. When the difference between mass number and atomic number of atoms of two or more elements are same, the atoms are known as

  1. Isotopes
  2. Isobars .
  3. Isotones
  4. Nuclear isomers

Answer: Isotones

16. Half-life period of a radioactive is calculated by:-

Half-life period of a radioactive

Answer: a)

17. The atomic number of the element is equal to the

  1. Number of protons
  2. Number of neutrons
  3. Slim of number of protons & neutrons
  4. None of the above

Answer: Number of protons

18. P- rays are

  1. +vely charged
  2. -vely charged
  3. Neutral
  4. None of the above

Answer: -vely charged

19. During the emission of a P-particle:-

  1. Atomic number increases by 1 unit & there is no change in the mass number
  2. Atomic number decreases by 2 unit, mass number decreases by 4 unit
  3. Atomic number and mass number remains same
  4. Atomic number and mass number both get increased

Answer: Atomic number and mass number remains same

20. P-10 gas is

  1. Mixture of 10% argon and 90% methane
  2. Mixture of 90% argon and 10% air
  3. Mixture of 90% argon and 10% oxygen
  4. Mixture of 90% argon and 10% methane

Answer. mixture of 90% argon and 10% methane

21. The energy resolution of the proportional counter is in the range of

  1. 1-5%
  2. 5-7%
  3. 5-15%
  4. 5-10%

Answer: 5-10%

22. The function of quenching vapour are:-

  1. To ionise the ionising radiation
  2. Produce amplitude for incident radiation
  3. To prevent the false pulses
  4. All of the above

Answer: To prevent the false pulses

23. Which is the commonly used quenching agent?

  1. Chlorine & Bromine
  2. Methane
  3. Argon
  4. Alcohol

Answer: Chlorine & Bromine

24 Which one of the following is not the gas-filled detector?

  1. Ionisation chamber
  2. Proportional counter
  3. Geiger-Muller counter
  4. Scintillation detector

Answer: Scintillation detector

25. Molecular formula of Barium sulphate is:-

  1. BaSO4
  2. Ba2SO4
  3. Ba(SO4)2
  4. BaSO3

Answer: BaSO4

Antimicrobials Resistance Notes

Antimicrobials

An antimicrobial (disinfectant and antiseptic) is a substance that kills or inhibits the growth of microorganisms such as bacteria, fungi or protozoans ntimicrobial drugs either kill microbes (microbiocidial) or prevent the growth of microbes (microbiostatic).

Specific terminology describes exact mode or mechanism of action.

Antiseptics: Antiseptic is a substance that prevents or arrests the growth of action of microorganisms. It acts by inhibiting their activity or destroying them especially of agents applied to living tissue like surface of skin, application of antiseptic dressings on wounds.

The drugs like phenol, iodine, boric acid, cetrimide are the examples of antiseptics.

Disinfectants: These are the drugs or substances used either to kill bacteria or prevent their growth or multiplication. It is used on non-living objects or outside the body.

For example : Disinfection of surgical instruments, sputum and urine containers on floor. Commonly used as disinfectants includes cresol, phenol.

Germicides: These are the substances which kill microorganisms. They act by oxidation of bacterial protoplasm, by denaturation of bacterial enzymes and proteins, by increasing permeability of bacterial cell membrane.

Potency of germicide is expressed by Phenol Coefficient. Specific terminology like bacteriocide (against bacteria), fungicide (against fungi), virucide (against virus) etc. denotes exact action.

Bacteriostatics: These are the substances which primarily function by inhibiting the growth of bacteria. Thus, bacteriostatic drugs or agents do not kill but arrest the growth of bacteria.

Read and Learn More Pharmaceutical Inorganic Chemistry Notes

Sanitizers: Sanitizer is the process of rendering sanitary by reducing the number of bacterial contaminants. These are used to maintain general public health standards.

Santization can be achieved only with surfaces and articles that are physically clean in addition to possess low bacterial counts or that are free from most vegetative microbes.

High cone, of sanitizers also cause local cellular damage. Inorganic compounds generally exhibit antimicrobial action by involving either of the following three mechanisms :

  1. Oxidation
  2. Halogenation
  3. Protein precipitation.

Boric Acid

Chemical Formula: H3BO3

Molecular Weight: 61.83

BORIC ACID

Synonyms : Hydrogen borate, boracic acid, orthoboric acid, acidum boricum.

It is widely distributed in sea water, plants and fruits. It is also available in the combined form as its largest natural source.

Method of Preparation

It is prepared by reading hydrochloric or sulphuric acid with the native borax.

The solution is filtered. The crystals obtained are washed and then allowed to dry at room temperature.

Properties

  1. It occurs as colourless or white crystals.
  2. It is slightly soluble in water and in alcohol.
  3. It is odourless with slightly acidic and bitter taste.
  4. On heating, it decomposes to form metaboric acid HBOr

Metaboric acid

Uses: Boric acid can be used as an antiseptic for minor bums or cuts. It is used in dressings or salves. It is applied in a very dilute solution as an eye wash. As an antibacterial or antimicrobial compound, it can also be used as an acne treatment.

Borax

Chemical Formula: Na2B4O7.10H2O

Molecular Weight: 381.4

Synonyms

Sodium Borate, Sodium Tetraborate, Sodium pyroborate

Properties

It occurs as colourless crystalline or white crystalline powder. It is having saline and alkaline taste. It loses all its water of crystallisation on ignition. It is odourless.

It efflorescences in dry air. It reacts with zinc salts to give zinc borate. Acidified and aqueous solution of sodium tetraborate on heating yield crystals of botfc acid.

BORAX

Uses
It finds use externally for eye washes and also used as an emulsifying agent for certain oils.

It is also used for softening of water.

Hydrogen Peroxide

Chemical Formula: H2O2

Molecular Weight: 34.016

It is an aqueous solution of hydrogen peroxide. It is having not less than 6% w/w of H O. which corresponds to about 20 times its volume of available 2: oxygen.
It was discovered by French chemist Thenard.

Methods of Preparation

In laboratory, it is prepared by Merck’s process. It is prepared by adding calculated V amounts of sodium peroxide to ice cold dilute (20%) solution of H2SO4.

HYDROGEN PEROXIDE

It is also prepared by the action of sulphuric acid or phosphoric acid on hydrated barium peroxide Ba02.8H20

HYDROGEN PEROXIDE

On commercial scale, H202 can be prepared by the electrolysis of 50% H2S04 solution. In a cell, peroxy sulphuric acid is formed at the anode.

HYDROGEN PEROXIDE

It is also obtained by decomposing barium peroxide with phosphoric acid or by passing carbon dioxide through a solution of barium peroxide in water.

HYDROGEN PEROXIDE

Properties

Hydrogen peroxide is clear, colourless syrupy liquid. It is odourless or may have an odour resembling to that of ozone unstable liquid. It has a specfic gravity of about 1.463 at 0°C. It is a strong oxidizing agent. It is soluble with water from which it can be extracted with solvent ether. It rapidly decomposes in contact with oxidizable organic matter and with metals.

Storage

H2O2 is not stored in glass bottles since the alkali metal oxides present in glass catalyse its decomposition It is stored in paraffin wax coated with glass, plastic or teflon bottles. Small amounts of acid, glycerol, alcohol, acetanilide and H3P04 often used as stabilizers to check its decomposition.

Uses

It acts as an antiseptic and a germcide and hence is used for cleaning cuts and wounds. It is used for bleaching delicate articles like wool, hair, feather, ivory etc. It is used as an aerating agents in production of spong rubber. It is used as an antichlor. It finds use in deodorants. It is also used for cleaning ears and removing the surgical dressing. It is an effective antidote for phosphorous and cyanide poisoning.

Potassium Permanganate

Chemical Formula: KMnO2

Molecular Weight: 158.03

It is an inorganic chemical compound having not less than 99.0% of KMnO2. Formerly known as Permanganate of Potash or Candy’s Crystals.

Method of Preparation

On large scale, it is prepared by mixing a solution of KOH with powdered manganese oxide and potassium chlorate in the presence of air or an oxidizing agent.

POTASSIUM PERMANGANATE

Potassium manganate so formed is extracted along with boiling water and a current of chlorine, C02 or ozonised air is passed into the liquid untill it gets converted to permanganate. The MnO2 formed is removed.

POTASSIUM PERMANGANATE

When carbon dioxide is passed through the chlorine solution, manganate gets converted into KMnO4

POTASSIUM PERMANGANATE

The solution of KMn04 is drawn off from any precipitate of Mn02 which is then concentrated and crystallized. The crystals are then centrifuged and dried.

Properties

It occurs as odourless dark purple or almost black prismatic crystals or granular powder. It has a sweet and astringent taste. It decomposes with a risk of explosion, in contact with certain organic substances.

It has a specific gravity of about 2.703. It is stable in air. It is soluble in water. When it is heated, it decomposes at a high temperature of about 240°C

Properties Of POTASSIUM PERMANGANATE

Alkaline or neutral solution of potassium permanganate is able to oxidize iodide to iodate

Properties Of POTASSIUM PERMANGANATE

In acidic medium iodine gets liberated from iodates.

Uses

It finds use in the treatment of urethritis. It possesses oxidizing properties and oxidizes proteins and other bioorganic substance. It has the capability to destroy the poison and prevents absorption.

Its solutions are used to clean the ulcer or abscesses, as wet dressings and in baths in eczematous condition. It finds use as an antidote in the case of poisoning by barbiturates, chloral hydrate and many alkaloids.

Chlorinated Lime Or Bleaching Powder Ca(OcI)CI

Chemical Formula : Ca(C1O)2

Molecular Weight: 136.98

Synonyms: Bleaching powder, chloride of lime.

Method of Preparation

It is prepared by the chlorination of slaked lime.

CHLORINATED LIME

It is usually a mixture of calcium hypochlorite (Ca(OCl)2) and calcium chloride with some slaked lime

Properties
It is dull white powder with characteristic odour. It is slightly soluble in water and in alcohoi. On exposure to air, it becomes moist and gradually decomposes with the loss of chlorine.

Its aqueous solution is strongly alkaline. It is able to oxidize many salts such as manganous salts to permanganate. Carbon dioxide gets absorbed and chlorine is evolved.

Uses

It is also used as an ingredient in bleaching powder, used for bleaching cotton and linen. It is also used in sugar industry for bleaching sugar-cane juice before its crystallization.

It is used as a sanitizer in outdoor swimming pools in combination with a cyanuric acid stabilizer which reduces the loss of chlorine due to ultraviolet radiation. It has the bactericidal action.

Iodine

Chemical Formula: I2

Molecular Weight: 253.8

Iodine I is a dark violet non-metallic halogen element.

Method of Preparation

Iodine is manufactured by extracting kelp (sea weed’s ash) with water. The solution is concentrated when the sulphate and chloride of sodium and potassium get crystallized out, leaving freely soluble sodium and potassium iodides in the mother liquor.

Sulphuric add is added to the mother-liquor which then gets decanted off.

IODINE

In the laboratory, it reacts by heating potassium iodide or sodium iodide with dilute sulphuric add and manganese dioxide.

IODINE

Properties

It occurs as heavy, bluish-black or greyish violet brittle plates with a metallic lusture. It is very slightly soluble in alcohol, chloroform and slightly soluble in concentrated solutions of iodides, carbon disulphide, solvent ether, carbon tetrachloride, chloroform, give violet solutions.

Uses

It is used as an anti-hyperthyroid. It is used in the manufacture of dyestuffs and drugs. It is used as a reagent in analytical chemistry. It is used in the manufacture of compounds used in Photography.

Prolonged use of iodine may produce metallic taste, increased salivation, burning pain. It can give rise to allergic reactions also.

Silver Nitrate

Chemical Formula: AgNO3

Molecular Weight: 169.89

It contains not less than 99.5% and not more than the equivalent of 100.5% of AgNO3.

Preparation

It is prepared by the reaction of silver with nitric acid which results into the formation of silver nitrate.

SILVER NITRATE

Properties

It occurs as colourless or white, odourless rhombic crystals. It is having a bitter caustic or metallic taste. It is highly soluble in boiling water when exposed to light or organic/blunder matter, it turns into grey or greyish black colour due to its reduction in metallic silver.

Uses

Silver salts have antiseptic properties. It is widely used as an astringent and germicide. Dilute solution of AgNO3 used to be dropped into new bom babies at birth to prevent contraction of gonorrhea from the mother.

Eye infection and blindness of new bom reduced by this method, incorrect damage, however could cause blindness in extreme cases.

Povidone-Iodine (Pv-I)

It is a stable chemical complex of Polyvinyl Pyrfolidonfe (povidone, PVP) and Elemental Iodine. It contains 9.0% to 12.0% available iodine, calculated on a dry basis. It belongs to iodophors class of compounds.

Properties

It is having a slight characteristic odour. It is a yellowish-brown amorphous powder. It is soluble in water and in alcohol but practically insoluble in organic solvents. It is acidic litmus.

Uses

It has a broad spectrum antiseptic for topical application in the treatment and prevention of infection in wounds. It is used as a disinfectant. It is also used as gargles and mouthwashes for the treatment of infections in the oral cavity.

Silver Protein

Chemical Formula: Variable

Molecular Weight : 169.89

Method of Preparation

It is obtained by treating silver salts with an excess of denaturated protein. The product is then dried in vaccum and finally stored in amber coloured bottles.

Properties

It occurs as dark brown or almost black shinning scales or granules. It is odourless and hygroscopic in nature. It is freely soluble in water but almost insoluble in alcohol, chloroform and ether.

When dissolved in water it forms colloidal solutions. It is affected by light and, therefore, should be protected from light. Mild silver protein solution in nitric acid yields a precipitate of silver chloride.

Uses

It is found to be useful in the treatment of infections of the respiratory tract through the prophylactic use which has been discontinued due to harmful nature. It possess to have mild antibacterial properties.

Mercury

Chemical Formula: Hg

Molecular Weight: 200.6

Synonym: Hydragyrum, Quick-silver

The Principle ore of Mercury is a red sulphide mineral called Cinnabar, HgS. It also occur as an amalgam of silver and gold and in small globules through rocks.

Preparation

It is obtained by roasting cinnabar in a current of air.

MERCURY

The free mercury gets liberated and further it gets purified by volatilisation or chemically by dropping mercury into a column of dilute nitric acid for removing basic impurities.

Properties

It occurs as shiny, silvery heavy liquid. It gets easily converted into the shape of globules. It readily volatiles on heating, its melting point is -38.9°C.

It is almost insoluble in water, alcohol and hydrochloric acid. It gets easily reacted by centrated sulphuric acid which results into the evolution of sulphuric dioxide and formation of mercuric sulphate.

Properties Of MERCURY

Uses

It is used as a Pharmaceutical Aid. It has Carthatic and Parasitic action. Its solution of salts have violent corrosive effects on skin and mucous membrane, nausea, vomiting, abdominal pain, bloody diarrhoea, kidney damage and death.

Compounds of mercury and its salts have declined greatly during this century.

Note

Avoid frequent or prolong contact of mercury with the skin. Mercury spills (zuhether in laboratory or in house from broken thermometer etc.) should be handled and collected with special care.

Yellow Mercuric Oxide

Chemical Formula: HgO

Molecular Weight: 216.16

Preparation

It is prepared by precipitation of mercuric nitrate or mercuric chloride with sodium hydroxide solution. The yellow precipitate obtained gets settle down and further washed by decantation.

It gets filtered and re-washed to separate chloride and further gets dried off in air.

Preparation Of YELLOW MERCURIC OXIDE

As the yellow precipitates gets affected by light, that is if all the reactions should be carried out in dark to maintain its orange yellow colour.

Properties

It is odourless orange yellow amorphous powder. Its colour varies from orange to yellow according to the temperature at which it is prepared. It gets decolourised on exposure to light. It is insoluble in water and alcohol but soluble in acids sch as HCl or H2SO4.

Properties Of YELLOW MERCURIC OXIDE

Uses

It has been used as a topical antiseptic, in conjunctivitis and in chronic ulcers. Due to its insolubility, it slowly releases Hg2+ ions which has mild sustained local antibacterial properties.

It is used in eye ointments for the local treatment of minor infections and inflammation of the eye including conjunctivitis.

Ammoniated Mercury

Chemical Formula: NH2HgCl

Molecular Weight: 252.1

AMMONIATED MERCURY

Synonym

Aminochloride of mercury, White precipitates.

Preparation

It is prepared by adding an aqueous solution of mercury chloride to ammonia solution with constant stirring. The precipitates so obtained gets filtered off and then washed with cold water to remove ammonium chloride. It is dried at a temperature not exceeding 30°C.

Preparation Of AMMONIATED MERCURY

Properties

It is a white heavy amorphous powder. It is odourless. It is almost insoluble in water, alcohol and ether but it is readly soluble in warm acetic acid. It is stable in air. It darkens on exposure to light.

It gets decomposed when dissolved in cold water. In boiling water, it gets hydrolyzed to yellow basic compound :- NH2HgCl; HgO

Properties Of AMMONIATED MERCURY

Uses

It is used in the treatment of skin diseases such as impetigo, in crab infections. Adverse effects include allergic reactions and mercury poisoning

Zinc Undecylenate

Chemical Formula : [CH2 = CH (CH2 )8 COO]2 Zn

Molecular wt: 431.9

Synonyms

Zinc Undecenoate, Zinc undec-10-enoate, Zinc undecyl.

Preparation

It is prepared by precipitation from a solution of sodium salt.

ZINC UNDECYLENATE

Properties

It is a fine white powder. It is stable and is practically insoluble in water and in alcohol.

Uses

It is topical antifungal agent.

Sodium Antimony Gluconate

Chemical Formula: C6H8NaO7Sb

Molecular Weight:‘336.88

Synonym: Antimony Sodium Gluconate

Method of Preparation

It is prepared by the action of sodium hydroxide on antimony trichloride and a solution of gluconic acid.

SODIUM ANTIMONY GLUCONATE

Properties

It is an odourless, white amorphous powder. It is soluble in water but insoluble in alcohol and solvent ether. Solution of Antimony Gluconate should be prepared immediately before use.

Uses
It is used in the treatment of leishmaniasis (Kala-azar) and as antischistosomal.

Antimicrobials Short Answer Questions

Question.1. Define Antimicrobials?
Answer. An antimicrobial (disinfectant and antiseptic) is a substance that kills or inhibits the growth of microorganism such as bacteria, fungi or protozoans.

Question.2. Classify antimicrobials on the basis of the exact mode or mechanism of action?
Answer.

  1. Antiseptic Bacteriostatics
  2. Disinfectant Sanitizers
  3. Germicides

Question.3. Define Antiseptic?
Answer. Antiseptic is a substance that prevents or arrests the growth of action of microorganisms.

Question.4. How do antiseptics act?
Answer. Antiseptics act by inhibiting the activity of microorganism or destroying them especially of agents applied to living tissues like surface of skin, application of antiseptic dressing on wounds.

Question.5. Write down the two examples of antiseptics?
Answer. Iodine, Boric acid, Cetrimide.

Question.6. Define Disinfectants?
Answer. Disinfectants are the drugs or substances used either to kill bacteria or prevent their growth or multiplication.

Question.7. Write down the two examples of disinfectants?
Answer. Cresol, Phenol.

Question.8. What is the difference between antiseptics and disinfectants?
Answer.

Antiseptics

  1. It is a substance that prevents or arrests the growth of microorganism.
  2. It is applied on living tissues.

Disinfectants

  1. It is a substance used either to kill bacteria or prevent their growth or multiplication. ,
  2. It is applied on non-living surfaces.

Question.9. What do you understand by the term Germicide? How do they act?
Answer. Germicides are the substances which kill micro-organisms.

Germicide act by oxidation of bacteria protoplasm, by denaturation of bacteria, enzymes and proteins.

Question.10. What is Bacteriostatic?
Answer. These are the substances which primarily function by inhibiting the growth of bacteria. Thus, bacteriostatic agents or drug do not kill but arrest the growth of bacteria.

Question.11. What do you understand by ‘Sanitizers’?
Answer. Sanitizer is the process of rendering sanitary by reducing the number of bacterial contaminants.

Question.12. Enlist various inorganic compounds that are used as Anitmicrobials?
Answer. Boric add, Borax, Hydrogen peroxide, Potassium permanganate, Chlorinated lime,Iodine.

Question.13. What is the chemical formula of Boric acid?
Answer. Chemical formula of Boric add is H3BO3.

Question.14. What is the method of preparation of Boric Acid?
Answer. Boric add is prepared by reacting hydrochloric or sulphuric add with the native borax to product orthoboric add.

BORIC ACID

The solution is then filtered off and the crystals obtained are washed and then allow to dry at room temperature.

Question.15. What is the chemical formula of Borax? By which other names they are known in the market?
Answer.

Borax: Na2B4O7.10H2O

Synonyms: Sodium borate, Sodium tetraborate, Sodium pyroborate

Question.16. What is the method of preparation of Hydrogen Peroxide?

Answer: Hydrogen peroxide is prepared by Marck’s process. It is prepared by adding calculated amounts of sodium peroxide to ice cold dilute (20%) solution of H2SO4.

HYDROGEN PEROXIDE

Question.17. Enlist the pharmaceutical uses of Hydrogen Peroxide?
Answer. Hydrogen peroxide is used as an antiseptic and a germicide. It is also used for cleaning cuts and wounds. It is an effective antidote for phosphorous and cyanide poisoning.

Question.18. What is the chemical formula and method of preparation for Potassium permanganate?
Answer. Chemical formula of potassium permanganate is KMnO4.

Potassium permanganate is prepared by mixing a solution of KOH with powdered manganese oxide and potassium chlorate in the presence of air or an oxidising agent and the mixture gets boiled.

POTASSIUM PERMANGANATE

Question.19. What are the Pharmaceutical uses of Potassium Permaganate?
Answer. Potassium permaganate solution is used to clean the ulcer or abcesses, as wet dressings and in baths of eczematous condition

Question.20. What is the chemical formula of Chlorinated Lime?
Answer. Ca(ClO)2

Question.21. What are the uses of Iodine?
Answer. Iodine is used as an antihyperthyroid. It is also used in the manufacture of dye stuffs and drugs.

Question.22. What is the method of preparation of Iodine in laboratory?
Answer. In laboratory, Iodine reacts by heating potassium iodide or sodium iodide wth dilute sulphuric acid and manganese dioxide.

Question.23. What is the general formula of Silver nitrate?
Answer. AgNO3

Question.24. What is the method of preparation of Silver nitrate?
Answer. Silver nitrate is prepared by the reaction of silver with nitric acid which result in the formation of silver nitrate.

SILVER NITRATE

Question.26. What are the other names of Mercury?
Answer. Hyedragyrum, Quick-silver.

Question.27. How do we prepare Mercury?
Answer. Mercury is obtained by roasting cinnabar in a current of air.

The free mercury gets librated and further it gets purified by volatilisation.

MERCURY

Question.28. What is the chemical formula of yellow mercuric oxide?
Answer. HgO.

Question.29. What is the chemical formula of Ammoniated Mercury?
Answer. NH2HgCl.

Question.30. How do we prepare ammoniated mercury?
Answer. Ammoniated mercury is prepared by adding an aqueous solution of mercury chloride to ammonia solution with constant stirring. The precipitates are obtained.

AMMONIATED MERCURY

Question.31. How do antimicrobials act?
Answer. Antimicrobial act by either oxidation, halogenation and protein precipitation.

Antimicrobials Fill In The Blanks

1. Antimicrobial is a substance that……………………

Answer: Kills or inhibits bacteria

2. Antimicrobial agents act by ………………….

Answer: Oxidation, halogenation and protein precipitation

3. Antiseptic are applied to…………… while disinfectants are applied to……………….

Answer: Living tissues, non-living objects

4………………..is the process of rendering sanitary by reducing the number of bacterial contaminants.

Answer: Sanitization

5. KMnO4can be used as an…………………………

Answer: Bactericidal, fungicidal, in the treatment of urethritis

6. KMnO4 is………………… reducing agents.

Answer: Strong oxidizing agent

7. Povidone-iodine is a member of class compound referred to as…………………………….

Answer: Iodophors

8. Povidone-Iodine is……………………………

Answer: Polyvinyl pyrollidine

9. Solution of AgNO3 can be used as an………………………

Answer: To prevent contraction of gonorrhea

10. Chemical formula of Ammoniated mercury is……………………

Answer: NH2HgCl

11. Ammoniated mercury is also known as…………………………

Answer: Aminochloride of mercury

12. …………………….include antiseptic, germdde and- disinfectant agent as well as sanitization process.

Answer: Iodine

13………………… give rise to hyperthyroidism symptoms of which are extreme fatigue,goitre.

Answer: Iodine

14. Diluted hydrogen peroxide (3% and 12%) is used to bleach human hair when mixed with ammonia and is called as…………………….

Answer: Peroxide blonde

15. Potassium permaganate is manufactured on a large scale by heating…………………. in the presence of air or as an oxidizing agent such as

Answer: Potassium hydroxide with manganese oxide, potassium nitrate

16. Yellow mercuric oxide is prepared by precipitation of………………………………..with………………….

Answer: Mercuric nitrate with sodium hydroxide

17. Mercury compounds as antimicrobial agents are . …………………..

Answer: Ammoniated mercury, yellow mercuric oxide

18. The chemical formula of Ammoniated Mercury is……………………..

Answer: NH2HgCl

19. Ammoniated mercury is also known as ………………………….

Answer: Aminochloride of mercury, white precipitates

20 ………………………..is prepared by precipitation of a solution of sodium salt.

Answer: Zinc undecylenate

21. The chemical formula of Sodium Antimony Gluconate is……………………..

Answer: C6H8NaO7Sb

22. Antimony gluconate is used as………………..

Answer: Antischistosomal

23……………………is prepared by reacting hydrochloric or sulphuric add. with the native borax to produce orthoboric add.

Answer: Boric acid

24. Hydrogen peroxide is…………………….solution.

Answer: Aqueous

25. ………….is an effective antidote for cyanide poisoning which is also used as an antimicrobial.

Answer: Hydrogen Peroxide

 

 

Pharmaceutical Inorganic Chemistry Practicals

Inorganic Chemistry Practicals

 Inorganic Chemistry Experiment No. 1

Aim:- To prepare and standardize 1 M sodium hydroxide (NaOH) solution.

Requirements:-

Chemicals required:- Sodium hydroxide, potassium biphthalate, phenolphthalein indicator.

Glassware required:- Burette, pipette, conical flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

Procedure:-

Preparation:

  1. Add about 4.2 gm of sodium hydroxide with continuous stirring.
  2. Add more about 700 ml of distilled water, mix and allow to cool to room temperature.
  3. Make up the volume 1000 ml with distilled water. Mix solution thoroughly.

Sodium Hydroxide Solution Standardization:

  1. Accurately weigh about 0.5 gm of potassium biphthalate, previously crushed lightly and dried at 120°C for 2 hrs.
  2. Dissolve in 75 ml of carbon dioxide free water.
  3. Add 2 drops of phenolphthalein, and titrate with sodium hydroxide solution to the production of a permanent pink colour.
  4. Each 20.42 mg of potassium biphthalate is equivalent to 1 ml of 0.1 N sodium hydroxide.

Calculation:

Read and Learn More Pharmaceutical Inorganic Chemistry Notes

M = Wt. of potassium biphthalate (gm) / 0.20423 * NaOH solution (ml)

 Inorganic Chemistry Experiment No. 2

AIM: TO Prepare and standardize 1 M hydrochloric acid (HCl) solution.

Requirements:-
.
Chemicals required:- sodium carbonate, hydrochloric acid, methyl indicator indicator.

Glassware required:- Burette, pipette, conical flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

Procedure:-

Preparation
.
Dilute 85 ml of hydrochloric acid with water to produce 1000 ml.

Standardization

  1. Weigh accurately about 1.5 gm of anhydrous sodium carbonate, previously heated to about 270°C for 1 hour.
  2. Dissolve it in 100 ml of water and add 0.1 ml of methyl red solution.
  3. Add the acid slowly from a burette, with constant stirring, until the solution become faintly pink.
  4. Heat the solution to boiling and titrate further as necessary until the faint pink colour is no longer affected by continued boiling.
  5. 1 ml of 1 M hydrochloric acid is equivalent to 0.05299 gm of Na2CO3.

Calculation

M=Na2CO3(mg) / HCl (ml) * 52.99

 Inorganic Chemistry Experiment No. 3

Aim:- To prepare and standardize 0.1 N potassium permanganate (KMnO4) solution.

Requirements:-

Chemicals required:- Potassium permanganate, sodium oxalate, sulphuric acid, methyl indicator.

Glassware required:- Burette, pipette, conical flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

Procedure:-

Preparation

  1. Dissolve 3.3 g of reagent grade potassium permanganate (KMnO4) in 1 L of purified water and heat on a steam bath for two hrs.
  2. Cover and allow to stand for 24 hrs.
  3. Filter through a fine porosity sintered glass crucible, discarding the first 25 mL. Store in a glass-stoppered, amber-colored bottle.
  4. Avoid exposure to direct sunlight; cover the neck of the bottle with a small beaker as protection against dust.

Standardization

  1. Weigh accurately 0.2-0.3 g sodium oxalate (Na2C2O4) (dried 2 hrs., 105-110 °C).
  2. Cool in a desiccator and transfer quantitatively to a 600 mL beaker.
  3. Add 250 mL of purified water (freshly boiled and cooled) and 10 mL sulphuric acid (96% H2S04, sp g 1.84).
  4. Add rapidly from a burette about 95% of the theoretical quantity of potassium permanganate solution needed; stir until the solution is clear.
  5. Heat the solution to 55-60 °C (Maintain temperature range during titration.) and complete the titration by slow drop wise addition until the appearance of a pink color whibh persists for 30 secs.
  6. Determine and subtract a blank titration run at 55-60 °C on a mixture of 250 mL of purified water (freshly boiled and cooled) and 10 mL of concentrated sulfuric acid.

Calculation

N= wt. of Na2C2O4(gm) *1000 /(Net Titre ml.) * 67.00

 Inorganic Chemistry Experiment No. 4

Aim- To prepare and standardize 1 N sodium thiosulphate (Na2S2O3) solution.

Requirements:-

Chemicals required:- Sodium thiosulphate, potassium dichromate, cone, hydrochloric acid , potassium iodide.

Glassware required:- Burette, pipette, conical flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

Procedure:-

Preparation

  1. Dissolve 25 g of sodium thiosulphate pentahydrate (Na2S203*5H20, 248 g/mol) in 1 liter of freshly boiled distilled water.
  2. For improve its stability by adding 0.1 g of Na2C03.
  3. Store overnight, and filter through fine grade paper, collect and store in a clean, dark glass bottle.

Standardization

  1. About 1.25gm of potassium dichromate is weighed out into a 250ml standard flask.
  2. It is dissolved in water & made up to the mark.
  3. 20ml of the made up solution is pipette out into a conical flask.
  4. About 3ml of concentrated HC1 is added, followed by 5ml of 10% potassium iodide solution.
  5. It is titrated against sodium thiosulphate solution from the burette using starch as indicator.
  6. Titration is repeated till concordant values are obtained.

Calculation

N= wt. of K2Cr2O7 (mg)/49.04 * Na2S2O3 (ml)

 Inorganic Chemistry Experiment No. 5

Aim:- To prepare and standardize .05 M disodium edetate (EDTA) solution.

Requirements:-

Chemicals required:- Disodium edetate, zinc, ammonia, sodium hydroxide, mordant black II .

Glassware required:- Burette, pipette, conical flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

Procedure:-

Preparation

Dissolve 18.6 g of disodium edetate in sufficient water to produce 1000 ml.

Standardization

  1. Weight accurately about 0.8 g of Granulated Zinc, dissolve by gentle warming in 12ml of diluted Hydrochloric acid and 0.1ml of bromine solution boil to remove the excess bromine, cool, add sufficient water to produce 200 ml.
  2. Pipette 20 ml in to a conical flask and nearly neutralize with 2 M sodium hydroxide.
  3. Add about 125 ml water and sufficient ammonia buffer pH 10 to dissolve the precipitate and add 5 ml in excess.
  4. Add 50 mg of mordant black II mixture and titrate with the prepared disodium edentate solution until the solution turns to green point.

Calculation

M = wt. of Zinc (gm) * 20/ 200 * 0.00654 * volume of EDTA (ml)

 Inorganic Chemistry Experiment No. 6

Aim:- Prepare and standardize 0. 1 M silver nitrate (AgNO3) solution.

Requirements:-

Chemicals required:- Silver nitrate, acetic acid, methanol, sodium hydroxide, Eosin Y indicator

Glassware required:- Burette, pipette, conical flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

Procedure:-

Preparation

  1. Take about 100 ml of water in a clean dried 1000 ml volumetric flask.
  2. Add about 17 gm of silver nitrate with continuous stirring.
  3. Add more about 700 ml of distilled water, mix.
  4. Make up the volume 1000 ml with water.
  5. Mix solution thoroughly.
  6. Keep the solution for at least one hour and then carry out the standardization.

Standardization

  1. Transfer about 50 mg, accurately weighed sodium chloride, previously dried at 110°C for 2 hours, to a 150 ml conical flask.
  2. Dissolve in 5 ml of distilled water.
  3. Add 2.5 ml of acetic acid, 25 ml methanol and about 0.25 ml of Eosin Y indicator.
  4. Stir with a magnetic stir.
  5. Titrate with the silver nitrate solution.

Calculation

M= NaCl (mg) / AgNO3 (ml) * 58.44

Primary And Secondary Standards

Primary Standard

A primary, standard is a reagent that is extremely pure, stable, it not a hydrate/has no water of hydration, and has a high molecular weight.

A primary standard should:

  • Be easy to store without deteriorating or reacting with that atmosphere.
  • Be readily obtainable in pure form.
  • Be in expensive.

Examples of primary standards for titration of acids are:

  • Sodium carbonate: Na2CO3, mol wt. = 105.99 g/mol
  • Tris-(hydroxymethyl)aminomethane (TRIS or THAM): (CH2OH)3CNH2, mol wt. =121.14 g/mol

Examples of primary standards for titration of bases are:

  • Potassium hydrogen phthalate (KHP): KHC8H4O4, mol wt. = 204.23 g/mol
  • Potassium hydrogen iodate: KH(IO3)2, mol wt. = 389.92 g/mol

Examples of primary standards for redox titrations are:

  • Potassium dichromate: K2Cr2O7, mol wt. = 294.19 g/mol
  • odium oxalate: Na2C2O4 mol wt. = 134.00 g/mol

Secondary Standard

A secondary standard is a standard that is prepared in the laboratory for a specific analysis. U is usually standardized against a primary standard.

Example:

An unknown solution of HC1 may be standardized volumetrically in two ways, namely:

  • By the help of ‘AnalaR’-grade Na2CO3 i.e., purity is known-primary Standard’, and
  • By the help of another standard solution of NaOH—‘Secondary Standard’,

Acid-Base Titrations

Acid-base titration is based on the neutralization reaction between acid and base. In this titration, the endpoint is a condition at which the moles of acid exactly cancel out the moles of base present in a solution or vice-versa. Hence the solution is neutral.

We can use the colour indicator like litmus paper and phenolphthalein to determine the endpoint. Potassium hydrogen phthalate calcium carbonate and oxalic acid strength of sample solution.

 Inorganic Chemistry Experiment No. 7

Aim:- To perform the assay of boric acid as per I.P.

Requirements:-

Chemicals required:- Boric acid (sample), sodium hydroxide, glycerol, phenolphthalein
indicator.

Glassware required:- Burette, pipette, conical flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

Principle:- Boric acid is very weak acid with very less dissociation constant. When it reacts with glycerol, glyceroboric acid is formed and its dissociation constant is increased and it behaves like strong acid.

Given sample of boric acid is dissolved in mixture of water and glycerin (1:2) and titrated against sodium hydroxide. End point can be detected by using phenolphthalein as an indicator.

Reaction involved in this titration is as follows.

boric acid

Procedure:-

Preparation of reagents and solutions:-

Preparation and standardization of sodium hydroxide (1 M)

Titration:-

  1. Clean and dry all glassware as per standard laboratory procedure.
  2. Rinse the burette with distilled water. Then, pre-rinse it with a portion of the NaOH solution before you fill it up for the titration. Pre-rinsing is necessary to ensure that all of the solution in the burette is the desired solution, not a diluted or contaminated solution.
    To do this, add about 10 ml of the NaOH solution to the clean burette. Carefully turn the burette on its side so the liquid slowly runs out the top. Rotate the burette on its axis during this time to make sure the solution wets the sides all the way to the top. Pour the rinse from the burette into a waste beaker. Repeat the rinsing process with a second portion of the NaOH solution.
  3. Weigh accurately about 1.0 g of H2BO3 in a conical flask and dissolve in mixture of 25 ml water and 50 ml glycerol.
  4. Add 2 drops of phenolphthalein indicator.
  5. Then fill the burette with standardized NaOH solution.
  6. Start titration with the NaOH until reach the endpoint. The first titration should be performed by adding 0.50 ml portions of NaOH solution from burette, with swirling. The approach of the endpoint is suggested by the temporary appearance of a pink colour that fades when the solution is swirled for upto 10 seconds. A pink colour that persists for more than 30 seconds signals the actual endpoint.
    Note:- The solution may lose its colour after 30 seconds or more, but it is not considered.
  7. The first titration gives a rough idea of the amount of NaOH needed to neutralize the H3BO3.
  8. Record the reading of burette.
  9. Repeat the titration three times to get precise readings. For these we can add about 70% of the needed NaOH quickly and then, near the end, add NaOH one drop at a time until the endpoint is observed.
  10. Take mean of them and calculate the percentage purity of H3BO3.

Observation Table:-
Observation Table

Calculations:-

Percentage purity = V X E X AM X 100/W x RM

Where,
V = volume of NaOH used (ml).
E = equivalent factor.
AM = actual molarity.
RM = required molarity.
W = weight of sample (g).

NOTE: The equivalent factor of H3BO3 for 1 ml of 1 M NaOH is 0.06183.

Result:- The percentage purity of boric acid was found to be

 Inorganic Chemistry Experiment No. 8

Aim:-  perform the assay of ammonium chloride as per I.P.

Requirements 

Chemicals required:- Ammonium chloride (sample), sodium hydroxide, glycerol,phenolphthalein indicator.

Glassware required:- Burette, pipette, conical flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

Principle:- Ammonium chloride is an expectorant, diuretic and systemic acidifier. It is an acidic salt which reacts with formaldehyde to liberate free acid, that free acid reacts with sodium hydroxide. End point can be detected by using phenolphthalein as an indicator. Reaction involved in this titration is as follows.

ammonium chloride

Procedure

Preparation and  standardization of sodium hydroxide (0. 1 M):-

Titration:-

  1. Clean and dry all glassware as per standard laboratory procedure.
  2. Rinse the burette with distilled water. Then, pre-rinse it with a portion of the NaOH solution before you fill it up for the titration. Pre-rinsing is necessary to ensure that all of the solution in the burette is the desired solution, not a diluted or contaminated solution.
    To do this, add about 10 ml of the NaOH solution to the clean burette. Carefully turn the burette on its side so the liquid slowly runs out the top. Rotate the burette on its axis during this time to make sure the solution wets the sides all the way to the top. Pour the rinse from the burette into a waste beaker. Repeat the rinsing process with a second portion of the NaOH solution.
  3. Weigh accurately about 0.1 g of NH4CI in a conical flask and dissolve in 20 ml distilled water.
  4. Add a mixture of 5ml formaldehyde solution and 20 ml distilled water.
  5. Add 2 drops of phenolphthalein indicator and allow to stand for two minutes.
  6. Then fill the burette with standardized NaOH solution.
  7. Start titration with the NaOH until reach the endpoint. The first titration should be performed by adding 0.50 ml portions of NaOH solution from burette, with swirling. The approach of the endpoint is suggested by the temporary appearance of a pink colour that fades when the solution is swirled for upto 10 seconds. A pink colour that persists for more than 30 seconds signals the actual endpoint
    Note:- The solution may lose its colour after 30 seconds or more, but it is not considered.
  8. The first titration gives a rough idea of the amount of NaOH needed to neutralize the free HCl.
  9. Record the reading of burette.
  10. Repeat the titration three times to get precise readings. For this we can add about 70% of the needed NaOH quickly and then, near the end, add NaOH one drop at a time until the the endpoint is observed.
  11. Take mean of them and calculate the percentage purity of NH4CI

Observation Table:

Observation Table

Calculations:-

Percentage purity = V x E X AM x 100/ W X RM

Where,
V = volume of NaOH used (ml).
E = equivalent factor.
AM = actual molarity.
RM = required molarity.
W= weight of sample (g).

NOTE: The equivalent factor of NH4Cl for 1 ml of 0.1 M NaOH is 0.005349.

Result: The percentage purity of ammonium chloride was found to be

 Inorganic Chemistry Experiment No. 9

AIM:- To perform the assay of sodium carbonate as per I.P.

Requirements.-

Chemicals required:- Sodium carbonate (sample), sodium hydroxide, methyl orange indicator.

Glassware required:- Burette, pipette, conical flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

PRINCIPLE:- Given sample of sodium carbonate is dissolved in water and titrated against hydrochloric acid. End point can be detected by using methyl orange as an indicator.

Reaction involved in this titration is as follows.

sodium carbonate

PROCEDURE:-

Preparation of reagents and solutions:-

Preparation and standardization of hydrochloric acid (1 M):-

Titration:-

  1. Clean and dry all glassware as per standard laboratory procedure.
  2. Rinse the burette with distilled water. Then, pre-rinse it with a portion of the HCl solution before you fill it up for the titration. Pre-rinsing is necessary to ensure that all of the solution in the burette is the desired solution, not a diluted or contaminated solution.
    To do this, add about 10 ml of the HCl solution to the clean burette. Carefully turn the burette on its side so the liquid slowly runs out the top. Rotate the burette on its axis during this time to make sure the solution wets the sides all the way to the top. Pour the rinse from the burette into a waste beaker. Repeat the rinsing process with a second portion of the HCl solution.
  3. Weigh accurately about 1.0 g of Na2CO3 in a conical flask and dissolve in 25 ml distilled water.
  4. Add 2 drops of methyl orange indicator.
  5. Then fill the burette with standardized HClsolution.
  6. Start titration with the HCl until reach the endpoint. The first titration should be performed by adding 0.50 ml portions of HCl solution from burette, with swirling. The approach of the endpoint is suggested by the temporary appearance of a pink colour that fades when the solution is swirled for uplo I0 seconds. A pink colour that persists for more than 30 seconds signals the actual endpoint.
    Note:- The solution may lose its colour after 30 seconds or more, but it is not considered.
  7. The first titration gives a rough idea of the amount of HCl needed to neutralize the Na2CO3.
  8. Record the reading of burette.
  9. Repeat the titration three times to gel precise readings. For this we can add about 70% of the needed HCI quickly and then, near the end, add HCI one drop at a time until the endpoint is observed.
  10. Take mean of them and calculate the percentage purity of Na2CO3.

Observation Table:

Observation Table

Calculations:-

Percentage purity =V XE xAM x 100/W x RM

Where,

V = volume of HCI used (ml).
E = equivalent factor.
AM ss actual molarity.
RM = required molarity.
W = weight of sample (g).

NOTE: The equivalent factor of sodium carbonate for I ml of 1 M HCl is 0.05299.

Result:

The percentage purity of sodium carbonate was found to be

 Inorganic Chemistry Experiment No. 10

Aim:- To perform the assay of sodium bicarbonate as per I.P.

Requirements:-

Chemicals required:-Sodium bicarbonate (sample), sodium hydroxide, methyl orange indicator

Glassware required:- Burette, pipette, conical flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

Principle:- Given sample of sodium bicarbonate is dissolved in carbon dioxide-free water and titrated against hydrochloric acid. End point can be detected by using methyl orange indicator.

Reaction involved in this titration is as follows.

sodium bicarbonate

Procedure:-

Preparation of reagents and solutions:-

Preparation and standardization of hydrochloric acid (1 M):-

Titration:-

  1. Clean and dry all glassware as per standard laboratory procedure.
  2. Rinse the burette with distilled water. Then, pre-rinse it with a portion of the HCl solution before you fill it up for the titration. Pre-rinsing is necessary to ensure that all of the solution in the burette is the desired solution, not a diluted or contaminated solution.
    To do this, add about 10 ml of the HCl solution to the clean burette. Carefully turn the burette on its side so the liquid slowly runs out the top. Rotate the burette on its axis during this time to make sure the solution wets the sides all the way to the top. Pour the rinse from the burette into a waste beaker. Repeat the rinsing process with a second portion of the HCl solution.
  3. Weigh accurately about 1 .5 g of Na2HCO3 in a conical flask and dissolve in 50 ml of carbon dioxide-free water.
  4. Add 2 drops of methyl orange indicator.
  5. Then fill the burette with standardized HCl solution.
  6. Start titration with the HCl until reach the endpoint. The first titration should be performed by adding 0.50 ml portions of HCl solution from burette, with swirling. The approach of the endpoint is suggested by the temporary appearance of a pink colour that fades when the solution is swirled for upto 10 seconds. A pink colour that persists for more than 30 seconds signals the actual endpoint.
    Note:- The solution may lose its colour after 30 seconds or more, but it is not considered.
  7. The first titration gives a rough idea of the amount of HCl needed to neutralize the
    Na2HCO3.
  8. Record the reading of burette.
  9. Repeat the titration three times to get precise readings. For these we can add about 70% of the needed HCl quickly and then, near the end, add HCl one drop at a time until the endpoint is observed.
  10. Take mean of them and calculate the percentage purity of Na2HCO3.

Observation Table:-

Observation Table

Calculations:-

Percentage purity = VxExAMx 100/W X RM

Where,
V = volume of HCl used (ml).
E = equivalent factor.
AM = actual molarity.
RM = required molarity .
W = weight of sample (g).

NOTE:- Equivalent factor of sodium bicarbonate for 1 ml of 1 M HCl is 0.08401.

Result:- The percentage purity of sodium bicarbonate was found to be

Redox Titrations

Redox titration involves the change in valency or oxidation states of reactants. Oxidation and reduction are takes place simultaneously in redox titration reaction. One substance is oxidized and other is reduced at a time.

Oxidation can be defined in following terms:-

Oxidation

The substance which loses electrons and get itself oxidized is called reducing agent. Some common reducing agents are antimony trioxide, ferrous sulphate, sodium thiosulphate, stannous chloride, oxalic acid etc.

Reduction can be defined in following terms:

Reduction

The substance which gain electrons and get itself reduced is called oxidizing agent. Some common oxidizing agents are potassium permanganate, potassium dichromate, potassium bromate, potassium iodate etc.

Redox titrations are of following types:-

  1. Permanganametry:- Titrations involving potassium permanganate.
  2. Iodimetry:- Titrations involving iodine.
  3. Iodometry:- Titration involving liberated iodine.
  4. Chromatometry:- Titrations involving potassium dichromate.
  5. Bromatometry:- Titrations involving bromine.

End point in redox titrations can be detected by using external indicator (starch paper), internal indicator (methylene blue), self indicator (potassium permanganate in permanganametry).

 Inorganic Chemistry Experiment No. 11

AIM:- To perform the assay of ferrous sulphate.

Requirements:-

Chemicals required:- Sulphuric acid, potassium permanganate, ferrous sulphate (sample).

Glassware required:- Burette, pipette, conical flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

Principle:- Ferrous sulphate is mainly used as hematinic and is a reducing agent. Assay of ferrous sulphate is an example of redox titration (permangnametry). Potassium permanganate acts as an strong oxidizing agent in acidic medium that oxidizes divalent ferrous sulphate to trivalent ferric sulphate.

Known strength of potassium permanganate is titrated with ferrous sulphate. End point can be detected with appearance of permanent pink colour, potassium permanganate acts as self indicator. Reaction involved in this titration is as follows.

ferrous sulphate

Procedure:-

Preparation of reagents and solutions:-

  1. Preparation and standardization of KMnO4 (0.1 N)
  2. Dilute sulphuric acid:- Dilute 57 ml of sulphuric acid to 1000 ml with distilled water.

Titration:-

  1. Clean and dry all glassware as per standard laboratory procedure.
  2. Rinse the burette with distilled water. Then, pre-rinse it with a portion of the KMnO4 solution before you fill it up for the titration. Pre-rinsing is necessary to ensure that all of the solution in the burette is the desired solution, not a diluted or contaminated solution.
    To do this, add about 10 ml of the KMnO4 solution to the clean burette. Carefully turn the burette on its side so the liquid slowly runs out the top. Rotate the burette on its axis during this time to make sure the solution wets the sides all the way to the top. Pour the rinse from the burette into a waste beaker. Repeat the rinsing process with a second portion of the KMnO4solution.
  3. Weigh accurately about 1 g of ferrous sulphate in a conical flask and dissolve in 20 ml of dilute sulphuric acid.
  4. Then till the burette with standardized KMn04 solution.
  5. Start titration with the KMnO4 solution until reach the endpoint. The approach of the endpoint is suggested by the temporary appearance of a pink colour that fades when the solution is swirled for upto 10 seconds. A pink colour that persists for more than 30 seconds signals the actual endpoint.
    NOTE:-The solution may lose its colour after 30 seconds or more, but it is-not considered.
  6. The first titration gives a rough idea of the amount of KMnO4 solution needed to reach the end point.
  7. Record the reading of burette.
  8. Repeat the titration three times to get precise readings.
  9. Take mean of them and calculate the percentage purity of ferrous sulphate.

Observation Table:-

Observation Table

Calculations:-

Percentage purity = V x E x AN x 100/W X RN

Where,
V = volume of KMn04 used (ml).
E = equivalent factor .
AN = actual normality of KMnO4.
RN = required normality of KMnO4.
W = weight of sample (g).

NOTE:- Equivalent factor of ferrous sulphate for 1 ml of 0.1 N KMnO4 is 0.02789.

Result: The percentage purity of ferrous sulphate was found to be

 Inorganic Chemistry Experiment No. 12

Aim:- To perform the assay of ferrous ammonium sulphate (Mohr’s salt).

Requirements:-

Chemicals required:- Sulphuric acid, ferrous ammonium sulphate (sample), potassium perman ganate.

Glassware required:- Burette, pipette, conical flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

Principle:- Ferrous ammonium sulphate is also known as Mohr’s salt. Assay of ferrous ammonium sulphate is an example of redox titration (permangnametry). Potassium permanganate acts as an strong oxidizing agent in acidic medium that oxidizes divalent ferrous sulphate of mohr’s salt to trivalent ferric sulphate.

Known strength of potassium permanganate is titrated with Ferrous ammonium sulphate. End point can be detected with appearance of permanent pink
colour, potassium permanganate acts as self indicator.

Reaction involved in this titration is as follows.

ferrous ammonium sulphate

Procedure:-

Preparation of reagents and solutions:-

  1. Preparation and standardization of KMnO4 (0.1N):-
  2. Dilute sulphuric acid:- Dilute 57 ml of sulphuric acid to 1000 ml with distilled water.

Titration:-

  1. Clean and dry all glassware as per standard laboratory procedure.
  2. Rinse the burette with distilled water. Then, pre-rinse it with a portion of the KMnO4 solution before you fill it up for the titration. Pre-rinsing is necessary to ensure that all of the solution in the burette is the desired solution, not a diluted or contaminated solution.
    To do this, add about 10 ml of the KMnO4 solution to the clean burette. Carefully turn the burette on its side so the liquid slowly runs out the top. Rotate the burette on its axis during this time to make sure the solution wets the sides all the way to the top. Pour the rinse from the burette into a waste beaker. Repeat the rinsing process with a second portion of the KMnO4 solution.
  3. Weigh accurately about 1 g of ferrous ammonium sulphate in a conical flask and dissolve in the mixture of 20 ml distilled water and 20 ml of dilute sulphuric acid.
  4. Then fill the burette with standardized KMnO4 Solution.
  5. Start titration with the KMnO4 solution until reach the endpoint. The approach of the endpoint is suggested by the temporary appearance of a pink colour that fades when the solution is swirled for upto 10 seconds. A pink colour that persists for more than 30 seconds signals the actual endpoint.
    NOTE:- The solution may lose its colour after 30 seconds or more, but it is not considered.
  6. Record the reading of burette.
  7. Repeat the titration three times to get precise readings.
  8. Take mean of them and calculate the percentage purity of ferrous ammonium sulphate.

Observation Table:-

Observation table

Calculations:

Percentage purity = V x E x AN X 100/W x RN

Where,

V = volume of KMnO4 used (ml).
E = equivalent factor.
AN = actual normality of KMnO4.
RN = required normality of KMnO4.
W= weight of sample (g).

Note:-  Equivalent factor of ferrous ammonium sulphate for 1 ml of 0.1 N KMnO4 is 0.03921.

Result:- The percentage purity of ferrous ammonium sulphate was found to be

 Inorganic Chemistry Experiment No. 13

Aim: Perform the assay of copper sulphate.

Requirements:-

Chemicals required:- Sodium thiosulphate, potassium iodide, acetic acid, potassium thiocyanate, starch indicator, copper sulphate (sample).

Glassware required:- Burette, pipette, conical flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

Principle:- Assay of copper sulphate is an example of iodometric titration. In the presence of acetic acid, Copper sulphate reacts with potassium iodide and give cupric iodide.

copper sulphate

Cupric iodide decomposes into cuprous iodide and liberate free iodine due to unstability.

copper sulphate

Known strength of sodium thiosulphate is titrated with liberated free iodine. End point can be detected by using starch as an indicator.

copper sulphate

Decomposition of cupric iodide to cuprous iodide is reversible. Potassium thiocyanate is added towards the end of reaction to convert cuprous iodide into cuprous thiocyanate which is more sparingly soluble than cuprous iodide.

copper sulphate

Procedure;-

Preparation of reagents and solutions:-

Preparation and standardization of Na2S2O3 (0.1 N):-

Titration:-

  1. Clean and dry all glassware as per standard laboratory procedure.
  2. Rinse the burette with distilled water. Then, pre-rinse it with a portion of the Na2S2O3 solution before you fill it up for the titration.  Pre-rinsing is necessary to ensure that all of the solution in the burette is the desired solution, not a diluted or contaminated solution.
    To do this, add about 10 ml of the Na2S2O3 solution to the clean burette. Carefully turn the burette on its side so the liquid slowly runs out the top. Rotate the burette on its axis during this time to make sure the solution wets the sides all the way to the top. Pour the rinse from the burette into a waste beaker. Repeat the rinsing process with a second portion of the Na2S2O3 solution.
  3. Weigh accurately about 1 g of copper sulphate in a conical flask and dissolve in 50 ml of distilled water.
  4. Add 3 g of potassium iodide and 5 ml acetic acid.
  5. Add 2 to 3 drops of starch indicator.
  6. Then fill the burette with standardized Na2S2O3 solution.
  7. Start titration with the Na2S2O3 solution. Continue titration until temporary appearance of a faint blue colour that fades when the solution is swirled for upto 10 seconds. Continue further untill blue colour that persists for more than 30 seconds.
  8. Add 2 g of potassium thiocyanate and stirr well.
  9. Continue titration untill blue colour disappears.
  10. The first titration gives a rough idea of the amount of Na2S2O3 solution needed.
  11. Record the reading of burette.
  12. Repeat the titration three times to get precise readings.
  13. Take mean of them and calculate the percentage purity of copper sulphate.

OBSERVATION TABLE:-

Observation table

Calculations:-

Percentage purity = V x E x AN x 100/W xRN

Where,
V= volume of Na2S2O3 used (ml).
E = equivalent factor .
AN = actual normality of Na2S2O3.
RN = required normality of Na2S2O3.
W = weight of sample (g).

NOTE:- Equivalent factor of copper sulphate for 1 ml of 0.1 N Na2S2O3 is 0.02497.

Result:- The percentage purity of copper sulphate was found to be

Complexometric Titration

Complexometric titration involves titration between metal ions and complexing agent or chelating agent (Ligand). This titration is based on the analytical application of a complexation reaction.

In this method, an ion is changed into a complex ion and the equivalence point is determined with the help of metal indicators or electrometrically. An EDTA (disodium edetate) is a popular complexing agent or chilon. The chilons react with metal ions to form a special type of complex known as chelate

 Inorganic Chemistry EXPERIMENT NO. 14

Aim: To perform the assay of magnesium sulphate as per I.P.

Requirements:-

Chemicals required:- Magnesium sulphate (sample), EDTA, mordant black ammonia, ammonium chloride.

Glassware required:- Burette, pipette, conical flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

Principle:- Magnesium sulphate is titrated directly against disodium edetate in the presence of strong ammonia-ammonium chloride solution. End point is detected by mordant black 11 mixture as an indicator.

Reaction involved in this titration is as follows.

magnesium sulphate

Procedure:-

Preparation of reagents and solutions:-

  1. Preparation and standardization of disodium edetate (0.05 M)
  2. Strong ammonia-ammonium chloride solution:- Mix 10 ml of water with 20 ml strong ammonia solution and saturate it with ammonium chloride.

Titration:-

  1. Clean and dry all glassware as per standard laboratoiy procedure.
  2. Rinse the burette with distilled water. Then, pre-rinse it with a portion of the disodium edetate solution before you fill it up for the titration. Pre-rinsing is necessary to ensure that all of the solution in the burette is the desired solution, not a diluted or contaminated solution.
    To do this, add about 10 ml of the disodium edetate solution to the clean burette. Carefully turn the burette on its side so the liquid slowly runs out the top. Rotate the burette on its axis during this time to make sure the solution wets the sides all the way to the top. Pour the rinse from the burette into a waste beaker. Repeat the rinsing process with a second portion of the disodium edetate solution.
  3. Weigh accurately about 0.3 g of magnesium sulphate in a conical flask and dissolve in 50 ml of distilled water.
  4. Add 10 ml of strong ammonia-ammonium chloride solution.
  5. Add 2 drops of mordant black ll mixture as an indicator.
  6. Then fill the burette with standardized disodium edetate solution.
  7. Start titration with the disodium edetate until reach the endpoint. The approach of the endpoint is suggested by the change of pink colour to blue.
  8. Record the reading of burette.
  9. Repeat the titration three times to get precise readings.
  10. Take mean of them and calculate the percentage purity of magnesium sulphate.

Observation Table:

Observation table

Calculations:-

Percentage purity = V x E X AM x 100/W X RM

Where,
V = volume of disodium edetate used (ml).
E = equivalent factor.
AM = actual molarity.
RM = required molarity.
W = weight of sample (g).

Note:- Equivalent factor of magnesium sulphate for 1 ml of 0.05 M disodium edetate is 0.00602.

Result:  The percentage purity of magnesium sulphate was found to be

 Inorganic Chemistry Experiment No. 15

Aim:- To perform the assay of calcium gluconate as per I.P.

Requirements:-

Chemicals required:- Calcium gluconate (sample), EDTA, mordant black II mixture, ammonia, ammonium chloride.

Glassware required:- Burette, pipette, conical flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

Principle:- This is a replacement titration. Magnesium forms complex with mordant black ll mixture indicator which shows first colour.

calcium gluconate

Magnesium-indicator complex is much more stable than calcium-indicator complex therefore calcium has not any effect on magnesium-indicator complex. On titration against disodium edetate complex of calcium and disodium edetate is formed.

calcium gluconate

When calcium is totally consumed, next drop of disodium edetate breaks the magnesium indicator complex and make complex with magnesium by liberating free indicator. End point is detected by observing second colour at that time.

calcium gluconate

Procedure:-

Preparation of reagents and solutions:

  1. Preparation and standardization of disodium edetate (0.05 M)
  2. Preparation of MgSO4 (0.05 M):- Accurately weigh about 600 mg of anhydrous magnesium sulphate and dissolve in 100 ml of distilled water.
  3. Strong ammonia-ammonium chloride solution:- Mix 10 ml of water with 20 ml strong ammonia solution and saturate it with ammonium chloride.

Titration:-

  1. Clean and dry all glassware as per standard laboratory procedure.
  2. Rinse the burette with distilled water. Then, pre-rinse it with a portion of the disodium edetate solution before you fill it up for the titration. Pre-rinsing is necessary to ensure that all of the solution in the burette is the desired solution, not a diluted or contaminated solution.
    To do this, add about 10 ml of the disodium edetate solution to the clean burette. Carefully turn the burette on its side so the liquid slowly runs out the top. Rotate the burette on its axis during this time to make sure the solution wets the sides all the way to the top. Pour the rinse from the burette into a waste beaker. Repeat the rinsing process with a second portion of the disodium edetate solution.
  3. Weigh accurately about 0.5 g of calcium gluconate in a conical flask and dissolve in 50 ml of warm water. Allow to cool.
  4. Add 5 ml of 0.05 M magnesium sulphate.
  5. Add 10 ml of strong ammonia-ammonium chloride solution.
  6. Add 2 drops of mordant black 11 mixture as an indicator.
  7. Then fill the burette with standardized disodium edetate solution.
  8. Start titration with the disodium edetate until reach the endpoint. The approach of the endpoint is suggested by the change in colour.
  9. Record the reading of burette (A)
  10. Repeat the titration three times to get precise readings.
  11. Take mean of them and calculate the percentage purity of calcium gluconate.
  12. Repeat the titration again using same procedure without calcium gluconate for blank reading

Observation Table:-

Observation table

Calculations:-

Percentage purity = V x E x AM x 100/W X RM

Where,
V= volume of disodium edetate used (ml).
V= A-B
A = volume of EDTA used in titration with calcium gluconate.
B = volume of EDTA used in titration without calcium gluconate.
E = equivalent factor.
AM = actual molarity.
RM = required molarity.
W = weight of sample (g).

Note: The equivalent factor of calcium gluconate for 1 ml of 0.05 M disodium edetate is 0.02242.

Result:- The percentage purity of calcium gluconate was found to be

 Inorganic Chemistry Experiment No. 16

AIM:- To perform the assay of calcium lactate as per I.P.

Requirements:-

Chemicals required:- Calcium lactate (sample), EDTA, mordant black 11 mixture, ammonia,anhydrous magnesium sulphate, ammonium chloride.

Glassware required:- Burette, pipette, conical flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

Principle:- This is a replacement titration. Magnesium forms complex with mordant black 11 mixture indicator which shows first colour.

calcium lactate

Magnesium-indicator complex is much more stable than calcium-indicator complex therefore calcium has no any effect on magnesium-indicator complex, on titration against disodium edetate complex of calcium and disodium edetate is formed.

calcium lactate

When calcium is totally consumed, next drop of disodium edetate breaks the magnesiumindicator complex and make complex with magnesium by liberating free indicator. End point is detected by observing second colour at that time.

calcium lactate

Procedure:

Preparation of reagents and solutionsi-

  1. Preparation and standardization of disodium edetate (0.05 M)
  2. Preparation of MgSO (0.05 M):- Accurately weigh about 600 mg of anhydrous magnesium sulphate and dissolve in 100 ml of distilled water.
  3. Strong ammonia-ammonium chloride solution:- Mix 10 ml of water with 20 ml strong ammonia solution and saturate it with ammonium chloride.

Titration:-

  1. Clean and dry all glassware as per standard laboratory procedure.
  2. Rinse the burette with distilled water. Then, pre-rinse it with a portion of the disodium edetate solution before you fill it up for the titration. Pre-rinsing is necessary to ensure that all of the solution in the burette is the desired solution, not a diluted or contaminated solution.
    To do this, add about 10 ml of the disodium edetate solution to the clean burette. Carefully turn the burette on its side so the liquid slowly runs out the top. Rotate the burette on its axis during this time to make sure the solution wets the sides all the way to the top. Pour the rinse from the burette into a waste beaker. Repeat the rinsing process with a second portion of the disodium edetate solution.
  3. Weigh accurately about 0.3 g of calcium lactate in a conical flask and dissolve in 50ml of distilled water.
  4. Add 5 ml of 0.05 M magnesium sulphate.
  5. Add 10 ml of strong ammonia-ammonium chloride sloution.
  6. Add 2 drops of mordant black 11 mixture as an indicator.
  7. Then fill the burette with standardized disodium edetate solution.
  8. Start titration with the disodium edetate until reach the endpoint. The approach of the endpoint is suggested by the change in colour.
  9. Record the reading of burette (A)
  10. Repeat the titration three times to get precise readings.
  11. Take mean of them and calculate the percentage purity of calcium lactate.
  12. Repeat the titration again using same procedure without calcium lactate for blank reading (B)

Observation Table:-

Observation table

Calculations:-

Percentage purity = V x E x AM x 100/W X RM

Where,
V = volume of disodium edetate used (ml).
V= A-B
A = volume of EDTA used in titration with calcium lactate.
B = volume of EDTA used in titration without calcium lactate.
E = equivalent factor.
AM = actual molarity.
RM = required molarity’.
W = weight of sample (g).

NOTE:- Equivalent factor of calcium lactate for 1 ml of 0.05 M disodium edetate is 0.01091.

Result: The percentage purity’ of calcium lactate was found to be

Precipitation Titration

Precipitations titration involves the formation of precipitate. Silver nitrate is the most important precipitating agent The titration which uses silver nitrate as precipitating agent is also called argentometric titration.

End point in precipitation titrations can be detected by using potentiometric or amperometric methods, indicators like potassium chromate, ferric ammonium sulphate or by adsorption indicators like rhodamine dye.

Mohr’s method is commonly used method in precipitation titrations for determination of halides of sodium and potassium. This is also called direct method. Sodium or potassium halides are allowed to react with silver nitrate solution.

When all the halides are precipitated by silver nitrate by formation of silver halides, then silver nitrate reacts with potassium chromate solution to give a red precipitate i.e. end point, due to formation of silver chromate.

Volhard’s method is also commonly used to determine halide content in an acidic solution. Known amount of excess silver nitrate solution is allowed to react with halides, which results in precipitates of silver halide.

Precipitates are separated by filtration and excess unreacted silver nitrate solution is determined by titration with standard ammonium thiocyanate solution using ferric alum as indicator.

 Inorganic Chemistry Experiment No. 17

Aim:- To perform the assay of sodium chloride. (Mohr’s method)

Requirements:-

Chemicals required:- Sodium chloride (sample), potassium chromate, silver nitrate.

Glassware required:- Burette, pipette, conical flask, volumetric flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

Principle:- Silver nitrate is titrated directly against sodium chloride and form white precipitate silver chloride with sodium nitrate.

sodium chloride

When all the chlorides of sodium chloride is consumed. It reacts with potassium chromate and end point can be detected with appearance of brick red colour due to formation silver chromate along with potassium nitrate.

sodium chloride

Procedure:-

Preparation of reagents and solutions:-

1. Preparation and standardization of silver nitrate (0.1 M)
2. Preparation of sodium chloride (sample) solution:- Weigh accurately about 1 g of sodium chloride (sample) and dissolve in 100 ml of distilled water.
3. Preparation of potassium chromate solution (5% w/v):- Weigh accurately about 5 g of potassium chromate and dissolve in 100 ml distilled water.

Titration:-

  1. Clean and dry all glassware as per standard laboratory procedure.
  2. Rinse the burette with distilled water. Then, pre-rinse it with a portion of the silver nitrate solution before you fill it up for the titration. Pre-rinsing is necessary to ensure that all of the solution in the burette is the desired solution, not a diluted or contaminated solution.
    To do this, add about 10 ml of the silver nitrate solution to the clean burette. Carefully turn the burette on its side so the liquid slowly runs out the top. Rotate the burette on its axis during this time to make sure the solution wets the sides all the way to the top. Pour the rinse from the burette into a waste beaker. Repeat the rinsing process with a second portion of the silver nitrate solution.
  3. Take 10 ml of sodium chloride (sample) solution in a conical flask.
  4. Add 2 to 3 drops of potassium chromate solution as an indicator.
  5. Then fill the burette with standardized silver nitrate solution.
  6. Start titration with the silver nitrate solution until reach the endpoint. The approach of the endpoint is suggested by the appearance of brick red colour.
  7. Record the reading of burette.
  8. Repeat the titration three times to get precise readings.
  9. Take mean of them and calculate the percentage purity of sodium chloride.

Observation Table:-

Observation table

Calculations:

Percentage purity = V x E x AM x 100/ W xRM

Where,
V = volume of silver nitrate used (ml).
E = equivalent factor.
AM = actual molarity.
RM = required molarity.
W = weight of sample (g).

NOTE:- Equivalent factor of sodium chloride for 1 ml of 0.1 M silver nitrate is 0.005845 .

Result: The percentage purity of sodium chloride was found to be

 Inorganic Chemistry Experiment No. 18

Aim:- To perform the assay of potassium chloride. (Mohr’s method)

Requirements:-

Chemicals required:- Potassium chloride (sample), potassium chromate, silver nitrate.

Glassware required:- Burette, pipette, conical flask, volumetric flask, funnel, beaker, glass rod.

Equipment required:- Weighing balance.

Principle:- Silver nitrate is titrated directly against potassium chloride and form white precipitate silver chloride with potassium nitrate.

potassium chloride

When all the chloride of potassium chloride is consumed. It reacts with potassium chromate and end point can be detected with appearance of brick red colour due to formation silver chromate along with potassium nitrate.

potassium chloride

Procedure:

Preparation of reagents and solutions:-‘

  1. Preparation and standardization of silver nitrate (0.1 M):-
  2. Preparation of potassium chloride (sample) solution:- Weigh accurately about 1 g of potassium chloride (sample) and dissolve in 100 ml of distilled water.
  3. Preparation of potassium chromate solution (5% w/v):- Weigh accurately about 5 g of potassium chromate and dissolve in 100 ml distilled water.

Titration:

  1. Clean and dry all glassware as per standard laboratory procedure.
  2. Rinse the burette with distilled water. Then, pre-rinse it with a portion of the silver nitrate solution before you fill it up for the titration. Pre-rinsing is necessary to ensure that all of the solution in the burette is the desired solution, not a diluted or contaminated solution.
    To do this, add about 10 ml of the silver nitrate solution to the clean burette. Carefully turn the burette on its side so the liquid slowly runs out the top. Rotate the burette on its axis during this time to make sure the solution wets the sides all the way to the top. Pour the rinse from the burette into a waste beaker. Repeat the rinsing process with a second portion of the , silver nitrate solution.
  3. Take 10 ml of potassium chloride (sample) solution in a conical flask.
  4. Add 2 to 3 drops of potassium chromate solution as an indicator.
  5. Then fill the burette with standardized silver nitrate solution.
  6. Start titration with the silver nitrate solution until reach the endpoint. The approach of the endpoint is suggested by the appearance of brick red colour.
  7. Record the reading of burette.
  8. Repeat the titration three times to get precise readings.
  9. Take mean of them and calculate the percentage purity of potassium chloride.

Observation Table:-

Observation table

Calculations:-

Percentage purity = V x E x AM x 100/ W xRM

Where,
V = volume of silver nitrate used (ml).
E = equivalent factor.
AM = actual molarity.
RM = required molarity.
W = weight of sample (g).

NOTE:- Equivalent factor of potassium chloride for 1 ml of 0.1 M silver nitrate is 0.007455.

Result:- The percentage purity of potassium chloride was found to be :

Non-Aqueous Titration

Non-aqueous titration involves the use of non aqueous solvents in it. Non-aqeous titrations are method of choice when reactants or products are insoluble in water, react with water or too weak acids or bases that cannot be titrated in water due to its levelling effect.

Commonly used solvents in non aqueous titrations are acetone, glacial acetic acid, formic acid, ethylene diamine, acetic anhydride and chloroform etc. End point can be detected by the indicators like crystal violet (0.5% in glacial acetic acid) and quinaldine red (0.1% in methanol) and by potentiometric methods.

Section D

Limit Test

Limit test is defined as quantitative or semiquantitative test designed to identify and control small quantity of impurity which is likely to be present in the substance. Limit test is generally carried out to determine the inorganic impurities present in the compound.

Limit test for chlorides, sulphates, iron, lead and heavy metal are carried out in Nessler cylinders. Nesseler cylinders are made up of borosilicate glass that is colourless.

It has the fixed diameter, length as per according to the Indian Pharmacopeia. Two similar kind of cylinders are required each time i.e. one for the ‘Test’ sample and other for the ‘standard’ to make comparison in the identical manner.

The quantities of the sample vary according to the limits of impurities while the standard remains constant. No numerical values for ths limits in these tests are prescribed in the pharmacopoeias, as it is not practicable.

Generally an aqueous solution of the substance is prepared. Sometimes a solution of the substance is prepared by dissolving in an acid or if the solution is alkaline it is neutralized with nitric or hydrochloric acid as specific in the monograph of the pharmacopoeia.

The extent of opalescence, turbidity and colour is affected by other impurities present in the substance.

 Inorganic Chemistry Experiment No. 19

AIM:- To perform the limit test for chlorides in the given sample (magnesium sulphate).

Requirements:

Chemicals required:- Sodium chloride, silver nitrate, sample (magnesium sulphate), dilute nitric
acid.

Glassware required:- Pair of Nessler cylinder, volumetric flask, beaker, measuring cylinder,glass rod, spatula, pipette.

Equipment required:- Weighing balance.

Principle:- This test is based on reaction between chloride ion and silver nitrate in the presence of nitric acid. It is an argentometric titration reaction. In this reaction chlorides are precipitated silver chloride.

When a small quantity of chloride ion is present in solution silver chloride shows opalescence while in large amount it precipitates. Opalescence of test sample is compared with standard in limit test for chlorides.

magnesium sulphate

Procedure:-

Preparation of reagents and solutions:

  1. Chloride standard solution (25 ppm chlorides):- Take 5 ml of 0.0824 % w/v solution of NaCl in 100 ml volumetric flask and make upto the mark with distilled water.
  2. Silver nitrate solution (0.1 M):- Dissolve 1.69 g of silver nitrate in 60 ml distilled water in 100 ml volumetric flask and make upto 100 ml with distilled water.

Preparation of test solution:-

  1. Weigh accurately about 1 g of magnesium sulphate or sample .
  2. Dissolve it in 10 ml of distilled water.
  3. Transfer the solution in Nessler cylinder and label it as “Test “.
  4. Add 10 ml dilute nitric acid.
  5. Make upto 50 ml mark with distilled water.
  6. Now add 1 ml 0.1 M silver nitrate solution in it.
  7. Stir with the glass rod and set aside for 5 minutes.

Preparation of standard solutions

  1. Add 10 ml standard chloride solution in Nessler cylinder and label it as “Standard “.
  2. Make upto 50 ml mark with distilled water.
  3. Now add 1 ml 0. 1 M silver nitrate solution in it.
  4. Stir with the glass rod and set aside for 5 minutes.

Observation:- Compare the opalescence of both test and standard solutions and write the observalion as follows:-

  1. If Test solution shows more opalescence than standard-limit test fails.
  2. If Test solution shows less opalescence than standard-limit test pass.

NOTE:- Compare these solutions in dark background i.e. black to get good contrast for comparison of the solutions.

Result:- Civen sample of magnesium sulphate pass / fails the limit test for chlorides.

 Inorganic Chemistry Experiment No. 20

Aim:- To perform the limit test for sulphates in given sample (sodium bicarbonate).

Requirements:

Chemicals required:- Sample (sodium bicarbonate), barium chloride, acetic acid, potassium sulphate.

Glassware required:- pair 0f Nessler cylinder, volumetric flask, beaker, measuring cylinder,glass rod, spatula, pipette.

Equipment required:- Weighing balance.

Principle: When sulphates interacts with barium chloride in the presence of acetic acid,sulphates precipitate as barium sulphate. When a small quantity of sulphates are present in solution, barium sulphate shows opalescence. The opalescence of test sample is compared with standard in limit test for sulphates.

To prevent the precipitation of other anions like phosphate, oxalate, borate etc with solution of barium chloride (which can affects the results), acetic acid is added. Therefore, in the presence of acetic acid, only sulphates are precipitated.

sodium bicarbonate

Procedure:-

Preparation of reagents and solutions:*

  1. Barium chloride solution (25 % w/v):- Dissolve 25 g of barium chloride in 100 ml distilled water stir well with glass rod .
  2. Ethanolic sulphate standard solution (10 ppm SO4-):- Take 1ml of 0.181% w/v solution of potassium sulphate in ethanol (30%) in 100 ml volumetric flask and make upto 100 ml with ethanol (30%).
  3. Sulphate standard solution (10 ppm SO4-):- Take
    potassium sulphate in distilled water in 100 ml volumetric flask and make upto 100 ml with distilled water.
  4. Sodium bicarbonate solution:- Dissolve 1.0 g of sodium bicarbonate in 1 ml of distilled water, then neutralize it with hydrochloric acid and dilute upto 15 ml with distilled water.

Preparation of test solution:-

  1. 1. Take lml barium chloride solution (25 % w/v) in Nessler cylinder.
  2.  Now add 1.5 ml of ethanolic sulphate standard solution (10 ppm SO2-4“) in it.
  3. Mix well and allow to stand it for 1 minute.
  4. Add 15 ml solution of sodium bicarbonate in it.
  5. Add 0.15 ml of 5 M Acetic acid.
  6. Make upto 50 ml with distilled water.
  7. Stir with the glass rod and set aside for 5 minutes.

Preparation of Standard solution:-

  1. Take 1 ml Barium chloride solution (25 % w/v) in Nessler cylinder.
  2. Now add 1.5 ml of ethanolic sulphate standard solution (10 ppm SO2-4) in it.
  3. Mix well and allow to stand it for 1 minute.
  4. Add 15 ml sulphate standard solution (10 ppm SO2-4) in it.
  5. Add 0.15 ml of 5 M acetic acid.
  6. Make upto 50 ml with distilled water.
  7. Stir with the glass rod and set aside for 5 minutes.

Observation:- Compare the opalescence of both test and standard solutions and write the observation as foliows:-

  1. If test solution shows more opalescence than standard – limit test fails.
  2. If test solution shows less opalescence than standard – limit test pass.

NOTE:- Compare these solutions in dark background i.e. black to get good contrast for comparison of the solutions.

Result:- Given sample of sodium chloride pass/fails the limit test for sulphates.

 Inorganic Chemistry Experiment No. 21

Aim: To perform the limit text for iron of given sample (sodium chloride).

Requirements:

Chemicals required:- Sample (sodium chloride), iron free citric acid solution (20% w/v) iron free ammonia solution, feme ammonium sulphate, thioglycollic acid, sulphuric acid.

Glassware required:- Pair of Ncsslcr cylinder, volumetric flask, beaker, measuring cylinder, glass rod, spatula, pipette.

Equipment required – Weighing balance.

Other requirements – pH paper.

Principle:- When iron interacts with thioglycollic acid in the presence of citric acid and the ammoniacal alkaline medium, ferrous salt of thioglycollic acid is produced which gives purple colour.

Colour intensity of lest sample is compared w ith standard in limit test for iron. To prevent the precipitation of iron with ammonia as iron hydroxides, citric acid is added. This keeps iron in solution form in the presence of ammonia.

NOTE:- Reagents used in this test must be completely free from iron otherwise false results will obtained.

sodium chloride

Procedure:

Preparation of reagents and solutions:

  1. Sodium chloride or sample, distilled water, iron free citric acid solution (20% w/v), iron free ammonia solution, thioglycollic acid.
  2. Iron standard solution (20 ppm Fe):- Take 1 ml of 0.1726 % w/v solution ferric ammonium sulphate in 0.05 M sulphuric acid make upto 10 ml with distilled water.

Preparation of test solution:-

  1. Weigh accurately about I g of sodium chloride or sample.
  2. Dissolve it in 40 ml of distilled water.
  3. Transfer the solution made in step 2 in Nessler cylinder and label it as “Test “.
  4. Add 2 ml iron free citric acid solution (20% w/v).
  5. Now add 0. 1 ml thioglycollic acid in it .
  6. Alkaline the solution with iron free ammonia solution.
  7. Dilute the solution upto 50 ml with distilled water.
  8. Stir with the glass rod and set aside for 5 minutes.

Preparation of Standard solution:-

  1. Add 2 ml iron standard solution (20 ppm Fe) in Nessler cylinder and label it as “Standard .
  2. Make upto 40 ml mark with distilled water.
  3. Add 2 ml iron free citric acid solution (20% w/v).
  4. Now add 0.1 ml thioglycollic acid in it.
  5. Alkaline the solution with iron free ammonia solution.
  6. Dilute the solution upto 50 ml with distilled water.
  7. Stir with the glass rod and set aside for 5 minutes.

OBSERVATION:- Compare the colour of both test and standard solutions and write the observation as follows:-

  1. If test solution shows more colour than standard – limit test fails.
  2. If test solution shows less colour than standard – limit test pass.

Results- Given sample of sodium chloride pass/fails the limit test for iron.

 Inorganic Chemistry Experiment No. 22

Aim:- To perform the limit test for heavy metais in given sample (sodium chloride).

Requirements:-

Chemicals required:- Sample (sodium chloride), hydrochloric acid, sulphuric acid, ammonia solution, saturated hydrogen sulphide solution, lead nitrate, nitric acid.

Glassware required:- pair 0f Nessler cylinder, volumetric flask, beaker, measuring cylinder, glass rod, spatula, pipette.

Equipment required:- Weighing balance.

Other requirements:- pH paper.

Principle: When hydrogen sulphide reacts with heavy metals (i.e. lead, antimony, bismuth ,tin, cobalt, manganese) in the presence of acidic medium, it produces metal sulphides.

These metal sulphides are distributed in colloidal state and produce brownish colour. Colour intensity of test sample is compared with standard in limit test for heavy metals.

NOTE:- Heavy metals like lead, antimony, bismuth, tin, cobalt, manganese are grouped together for their limit test in Indian. Pharmacopoeia and their quantity is expressed in the terms of lead.

sodium chloride

PROCEDURE:-

Preparation of reagents and solutions

  1. Standard lead solution (20ppm):- Weigh accurately about 400 mg of lead nitrate in distilled water containing 2 ml of nitric acid and dilute upto 250 ml. Take 10 ml of this solution and dilute upto 100 ml. Further take 10 ml of this solution and dilute upto 50 ml with distilled water.
  2.  Dilute acetic acid:- Dilute 57 ml of glacial acetic acid to 1000 ml with distilled water.

For Colourless Substances:-

Preparation of test solution:-

  1. Take 25 ml solution of test sample in Nessler cylinder and label it as “Test
    NOTE:- Prepare solution of test sample as directed in pharmacopoeia or otherwise dissolve specified quantity of test sample in 25 ml distilled water.
  2. Adjust the pH of solution between 3.0 to 4.0 with dilute acetic acid.
  3. Dilute upto 35 ml with distilled water.
  4. Mix well with glass rod.
  5. Now add 10 ml of freshly prepared saturated solution of hydrogen sulphide.
  6. Make the volume upto 50 ml with distilled water.
  7. Stir with the glass rod and set aside for 5 minutes.

Preparation of standard solution:-

  1. Take 2 ml standard lead solution (20 ppm) in Nessler cylinder and label it as “Standard “.
  2. Make upto 2 ml with distilled water.
  3. Adjust the pH of solution between 3.0 to 4.0 with dilute acetic acid.
  4. Dilute upto 35 ml with distilled water.
  5. Mix well with glass rod.
  6. Now add 10 ml of freshly prepared saturated solution of hydrogen sulphide.
  7. Make the volume upto 50 ml with distilled water.
  8. Stir with the glass rod and set aside for 5 minutes.

For Coloured Substances

Preparation of test solution:-

  1. Accurately weigh a quantity of substance as directed in pharmacopoeia or otherwise weigh specified quantity of sustance in a crucible.
  2. Wet it by sufficient quantity of sulphuric acid
  3. Ignite at low temperture until thoroughly charred.
  4. Add 2 ml nitric acid in charred mass and 5 drops of sulphuric acid.
  5. Heat until, white fumes no longer evolved from it.
  6. Ignite it, until carbon is completey burnt off at 500 to 600 °C.
  7. Allow to cool and add 4 ml hydrochloric acid in it.
  8. Digest it on water bath for about 15 minutes and evaporate to dryness.
  9. Add 1 drop of hydrochloric acid to moisten the residue.
  10. Now add 10 ml hot water and digest for 2 minutes.
  11. Alkaline the solution with dropwise addition of ammonia solution (just alkaline to the litmus paper).
  12. Make upto 25 ml with distilled water.
  13. Adjust the pH of solution between 3.0 to 4.0 with dilute acetic acid.
  14. Dilute upto 35 ml with distilled water.
  15. Mix well with glass rod .
  16. Now add 10 ml of freshly prepared saturated solution of hydrogen sulphide.’
  17. Make the volume upto 50 ml with distilled water.
  18. Stir with the glass rod and set aside for 5 minutes.

Preparation of Standard solution:-

Procedure same as Preparation of standard solution for colourless substances.

Observation:- Compare the colour of both test and standard solutions and observation as follows:-

  1. If test solution shows more colour than standard – limit test fails.
  2. If test solution shows less colour than standard – limit test pass.

Result: Given sample Of sodium chloride pass/ fails thnimit ttst for heavy metal (lead, antimony, bismuth, tin, cobalt, manganese).

 Inorganic Chemistry Experiment No. 23

Aim:- To perform (he limit test for arsenic in given sample (ammonium chloride).

Requirements:-

Chemicals required:- Sample (ammonium chloride), granulated zinc, potassium iodide, arsenic trioxide, sodium hydroxide, stannous chloride solution.

Glassware required:- Volumetric flask, beaker, measuring cylinde, glass rod, spatula, pipette.

Equipment required:- jwo sets of arsenic test apparatus, weighing balance.

Other requirements:- Cotton, mercuric chloride paper.

Principle:- when sample containing arsenic is dissolved in acid, arsenic impurity get converted into arsenious acid (trivalent) or arsenic acid (pentavalent) depending upon the valency state of arsenic present in sample.

ammonium chloride

On treatment with stannous chloride (reducing agent) pentavalent arsenic acid is converted into trivalent arsenious acid.

NOTE:- Potassium iodide is used in test because it facilitate the conversion of pentavalent arsenic acid into trivalent arsenious acid.

ammonium chloride

On treatment with stannous chloride (reducing agent) pentavalent arsenic acid is converted into trivalent arsenious acid.

ammonium chloride

With the help of nascent hydrogen produced by Zn + HCl, arsenious acid is converted into arsine gas (gaseous arsenious hydride)

Produced arsine gas is carried out through the tube by passing through mercuric chloride paper .When arsenic gas reacts with mercuric chloride, brown or yellow stain is produced on mercuric chloride paper. Intensity of colour produced is proportional to the quantity of arsenic present.

ammonium chloride

Similarly,, stain is produced for standard solution of arsenic and intensity of two stains is compared and results are noted down.

NOTE:- Reagents used in this test must be completely free or low in arsenic otherwise false results will obtained. They are commercially available.

Arsenic test apparatus: A wide-mouth Slass bottle which is fitted with a rubber bung and a glass tube with 200 mm length with internal diameter 6.5 mm and outer diameter 8.0 mm is passes through it.

Upper end of this tube is open and lower end is tapered by reducing diameter to l (diameter of glass tube is reduced at lower end for slow and smooth passage of arsine gas ).

At the side of lower end, a hole of 2 mm diameter is made from where the lower end starts tapering (this hole is made for the alternate passage for arsine gas if water condenses at lower end ).

Cotton wool moistened with lead acetate solution, dried and packed in glass tube. Lead cotton trap hydrogen sulphide gas if any, which can interfere with the test by giving stain on mercuric chloride paper.

Upper end of tube is fitted with two rubber bungs and act like tube of 6.5 mm diameter with the help of clips enclosing flat mercuric chloride paper in it.

Arsenic test apparatus

Procedure:-

Preparation of reagents and solutions:-

  1. Arsenic standard solution (10 ppm As):- Weigh accurately 0.330 g of arsenic trioxide and dissolve it in 5 ml of 2 M sodium hydroxide solution, dilute upto 250 ml with distilled water. Take 1ml of this solution and make upto 100 ml with distilled water.
  2. Stannated hydrochloric acid:- Add 1 ml of stannous chloride solution and make upto 100 ml with hydrochloric acid.

Preparation of test solution:-

  1. Add 50 ml distilled water in arsenic test apparatus bottle label this apparatus as “Test
  2. Weigh accurately and dissolve 2.5 g of ammonium chloride sample in it.
  3. Now add 10 ml stannated hydrochloric acid.
  4. Add 5 ml solution of 1 M potassium iodide.
  5. Now add 10 g of granulated zinc.
  6. Quickly place prepared glass lube at its position and allow to stand for 40 minutes.

Preparation of standard solutions-

  1. Add 50 ml distilled water in arsenic test apparatus bottle and label tills apparatus as Standard .
  2. Now add and mix 1 ml of arsenic standard solution (10 ppm As) in it.
  3. After mixing of step 2, add 10 ml stannated hydrochloric acid.
  4. Add 5 ml solution of I M potassium iodide.
  5. Now add 10 g of granulated zinc.
  6. Quickly place prepared glass tube at its position and allow to stand for 40 minutes.

Observation:- Compare the yellow stain of both test and standard solutions and write the observation as follows:-

  1. If test solution show yellow stain with more intensity than standard – limit test fails.
  2. If test solution show yellow stain with less intensity than standard – limit test pass.

Result:- Given sample of ammonium chloride pass/fails the limit test for arsenic.

 Inorganic Chemistry Experiment No. 24

Aim:- To perform modified limit test for chloride.

Requirements:-

Chemicals required:- Sodium benzoate, sodium salicylate, crystal violet, hypophosphorus acid

Glassware required:- Ncsslcr cylinder, measuring cylinder, glass road, beaker.

Procedure:

A specified amount of the substance is dissolved in distilled water, and the volume made up to 50 ml in a Nessler cylinder. Depending upon the nature of the substance, some modifications have to be adopted for the preparation of the solution.

  1. Alkaline substances have to be dissolved in acid so that effervescence ceases and much of the free acid is left in the solution as is prescribed in the test.
  2. Insoluble substances are generally extracted with water and then filtered, and the filtrate is used for the test, because the presence of insoluble substance modifies the opalescence and colour.
  3. Salts of organic acids like sodium benzoate, sodium, salicylate, etc. liberate free water insoluble organic acid during acidification which is filtered off and the filtrate is employed for the test.
  4. Coloured substances like crystal violet, malachite green, etc. are carbonised and the ash so produced is extracted in water.
  5. Deeply coloured substances have to be decolourised before test e.g., potassium permanganate is reduced by boiling with alcohol and the filtrate is used.
  6. Reducing substances like hypophosphorus acid, which react with silver nitrate in the limit test for chlorides should be oxidized with nitric acid or some other oxidizing agents before carrying out the test.

 Inorganic Chemistry Experiment No. 25

Aim:- To perform modified limit test for sulphate.

Requirements:-

Chemicals required:- Sodium benzoate, sodium salicylate, crystal violet, hypophosphorus acid

Glassware required:- Nessler cylinder, measuring cylinder, glass road, beaker.

Procedure:

A specified amount of the substance is dissolved in distilled water, and the volume made up to 50 ml in a Nessler cylinder. Depending upon the nature of the substance, some modifications have to be adopted for the preparation of the solution.

  1. Alkaline substances have to be dissolved in acid so that effervescence ceases and much of the free acid is left in the solution as is prescribed in the test.
  2. Insoluble substances are generally extracted with water and then filtered, and the filtrate is used for the test, because the presence of insoluble substance modifies the opalescence and colour.
  3. Salts of organic acids like sodium benzoate, sodium salicylate, etc. liberate free water insoluble organic acid during acidification which is filtered off and the filtrate is employed for the test.
  4. Coloured substances like crystal violet, malachite green, etc. are carbonised and the ash so produced is extracted in water.
  5. Deeply coloured substances have to be decolourised before test e.g., boiling with alcohol reduces potassium permanganate and the filtrate is used.
  6. Reducing substances like hypophosphorus acid, which react with silver nitrate in the limit test for chlorides should be oxidized with nitric acid or some other oxidizing agents before carrying out the test.

Section E

Identification Test

Identification tests are performed to determine the qualitative characteristics of material under examination. For the identification of inorganic drugs and pharmaceutical aids the tests are generally based on reactions of an anion and cation present in a molecule.

Identification Tests:

Aim: Identification tests are performed for the ferrous sulphate

Tests for Ferrous Salts:

Dissolve a quantity of the substance being examined equivalent to about 1 0 mg of iron in 1 ml of water or use 1 ml of prescribed solution. Add 1 ml dilute H2SO4and 0.1% w/v solution of 1,10-phenanthroline (1ml), an intense red colour is produced, which is discharged by addition of 0.1 M cerric ammonium sulphate is produced.

To a 1 ml solution containing net less than 1 mg of iron, add 1 ml potassium ferricyanide solution, a dark blue precipitate is formed that is insoluble in dilute HCl and is decomposed by sodium hydroxide solution.

ferrous sulphate

To a 1 ml of solution containing not less than 1 mg of iron add 1 ml potassium ferrocyanide solution, a white precipitate is formed which is rapidly become blue and us insoluble in dilute HCl.

ferrous sulphate

Tests for Sulphate:

Dissolve about 50 mg of the substance being examined in 5 ml of water or use 5 ml of prescribed solution. Add 1 ml of dilute HCl and 1 ml of barium chloride solution; a white precipitate is formed.

Sulphate

Add 0.1 ml of iodine solution to the suspension obtained in the test (1); the suspension remains yellow but is decolorised by adding stannous chloride solution drop wise. Boil the mixture; no coloured precipitate appears.

Dissolve the 50 mg Of substance being examined in 5 ml of water and add 2 ml of lead acetate solution; a white precipitate is formed which is soluble in ammonium acetate solution and in sodium hydroxide solution is produced .

Sulphate

Aim: Identification test for sodium bicarbonate

Tests for Sodium:

Dissolve 0.1 gm of the substance being examined in water and add 2ml of 15% w/v solution of potassium carbonate; heat to boiling; no precipitated is produced.

Add freshly prepared 4ml potassium antimonate solution and heat to boiling. Allow to cool in ice and if necessary scratch the inside of the test tube with help of glass rod; a dense, white precipitate is produced.

Sodium

Acidify a solution of the substance being examined with IMacetic acid and add excess of magnesium uranyl acetate solution, a crystalline, yellow precipitate is formed.

Sodium

Tests for Bicarbonate

Solutions of bicarbonate, when boiled, liberate CO2

Bicarbonate

Treat a solution of the substance being examined with a solution of magnesium sulphate; no precipitated is produced. Boil, white precipitate is formed.

Bicarbonate

Introduce into a test tube the 0.1 gm of the substance being examined suspended in 2 ml of water.

Add 2ml of 2M acetic acid, close the test tube immediately using a stopper fitted with a glass tube bent at two right angles, heat gently and collect the gas in 5 ml barium hydroxide solution; a white precipitate is produced that dissolve on addition of an excess of dilute HCl solution.

Bicarbonate

Aim: Identification test Calcium gluconate

Tests for Gluconic Acid:

To a solution of 3% w/v calcium gluconate (1 ml), add few drops of ferric chloride solution, a yellow colour appears.
Gluconic acid is an a-hydroxy acid. It reacts with ferric chloride to form a yellow floured complex.

To the sample (0.75 gm) in warm water (7.5 ml), add glacial acetic acid (1 ml) and freshly distilled phenylhydrazine (1.5 ml). Heat the mixture on a water bath for half an hour and allow to cool.

Scratch the inner surface of the tube with a glass rod until crystals of gluconic acid phenylhydrazine begin to form. Keep the test for 10 minutes, filter,dissolve the precipitate in hot water (10 ml), add small amount of decolourising charcoal and filter.

Allow to cool and scratch the test tube to recover the white crystals which melt at about 200°C with decomposition. Phenylhydrazine forms gluconic acid phenylhydrazine with gluconic acid which is purified by boiling with chalcoal and identified on the basis of melting point determination.

Tests for calcium Ion:

Dissolve 20 mg of substance being examined in 5M acetic acid (5ml) or add 1 ml glacial acetic.acid. Add 0.5 ml potassium ferrocyanide solution, the solution remains clear. Add 50 mg. ammonium chloride; a crystalline, white precipitate is produced.

Tests for calcium Ion

To a 0.4 % w/v solution of the substance (5 ml) add 0.2 ml of 2% w/v solution of ammonium oxalate; a white precipitate is obtained that is only sparingly soluble in dilute acetic acid but is insoluble in hydrochloric acid.

Tests for calcium Ion

Dissolve 20 m of the substance being examined in the minimum quantity of dilute HCl and neutralize with dilute NaOH solution.

Add 5ml ammonium’carbonate solution, a white precipitate is formed which after boiling and cooling is only sparingly soluble in ammonium chloride solution.

Tests for calcium Ion

 Inorganic Chemistry Experiment No. 26

Aim:- Identification test are performed for magnesium hydroxide.

Requirements:

Chemicals required:- Ammonium chloride, disodium hydrogen phosphate, amrponium hydroxide.

Test for Magnesium Salt:

15 gm of substance is dissolved in 2 ml of water and added 1ml of dilute ammonia solution to it; a white precipitate forms that is redissolved by adding 1ml of 2M ammonium chloride.

1 ml of 0.25 M disodium hydrogen phosphate is added; a white crystalline precipitate forms.

Ammonium chloride prevents precipitation by a common ion effect, it prevents precipitation of magnesium hydroxide due to suppression of dissociation of ammonium hydroxide.

magnesium hydroxide

Test for Hydroxide ion

Alkaline solution tests. When mixed with an ammonium salt and heated gently it produces an alkaline gas (fumes turn universal indicator paper blue)

 Inorganic Chemistry Experiment No. 27

Aim:- To perform the identification test for copper sulphate.

Requirements:-

Chemicals required:-Hyrochloric acid, potassium ferrocyanide TS, ammonium hydroxide.

Test for Copper Salt

Solution of cupric compounds, acidified with HCl, deposit a red film of metallic copper upon a bright, untarnished surface of metallic ion. Added an excess of 6N ammonium hydroxide to a solution of cupric salt, produce first a bluish precipitate than a deep blue coloured solution.

Solution of cupric salts yield a reddish-brown precipitate with potassium ferrocyanide TS, insoluble in dilute acid.

Tests For Purity

 Inorganic Chemistry Experiment No. 28

Aim:-To perform the swelling index of bentonite.

Requirement:-

Chemicals required:-Bentonite, Sodium Lauryl sulphate.

Apparatus required:- Beaker, glass rod, watch-glass, measuring cylinder.

Theory:-

It is a colloidal hydrated aluminum silicate which occurs naturally. The swell index is used to determine the general characteristics of bentonite. When water is added to the bentonite,each particle of it is surrounded by a layer of water.

This causes the swelling of particles and become several times larger than the original particle.

Procedure:-

  1. Dissolve1 gm of sodium lauryl sulphate in 100 ml of water and transfer it to a 100 ml of measuring cylinder.
  2. Weigh accurately 2 gm of bentonite and add it in into the above solution in small quantities after every 2 minutes. Allow each portion to settle.
  3. Set it aside for 24 hours
  4. Find out the apparent volume of the sediment at the bottom of the cylinder.

Observation:- The observation is one of the two given below:-

The apparent volume of the sediment the bottom is 24 ml or more.
The apparent volume of the sediment is less than 24 ml.

Result:- The report may be one of the two given below:-

  1. The sample passes the test
  2. The sample doesn’t pass the test.

Applications:-

  1. It is used as a bulk laxative and also used as a base for many dermatological formulas.
  2. It is an important ingredient of calamine lotion which is used as a protective.
  3. It is a good pharmaceutical aid and is used as a protective colloid to stabilize emulsions.
  4. It finds use as an emulisifier for oil in water emulsion.

 Inorganic Chemistry Experiment No. 29

Aim:- Acid-Neutralizing Capacity of Aluminum hydroxide Gel.

Requirements:-

Chemicals Required:-Aluminium hydroxide, hydrochloric acid

Apparatus Required:- 250 ml beaker, spatula; measuring cylinder

Theory:-AlUminum hydroxide reacts with hydrochloric acid to form aluminum chloride.

Aluminum hydroxide Gel

This means that aluminum hydroxide can act as a good antacid and will be able to neutralize the acid in the stomach.

Procedure:-

Add 5 gni. of tire sample into 100 ml of water in a beaker. Place the beaker in a thermostatic water bath and adjust to get 37°C in the suspension in the beaker. Add 100 ml of 0.1M hydrochloric acid, previously heated to 37°C.

Stir continuously maintaining the temperature at 37°C. Measure the pH of the solution at 37°C with the help of a pH meter after10, 15 and 20 minutes and record the same.

The pH should be more than 1.8 after 10 minutes, 2.3 after 15 minutes and 3 after 20 minutes.The pH at any time shouldn’t more than 4.5. Add 10 ml of 0.5 M hydrochloric acid, previously heated to 37 °C.

Stir continuously for one hour maintaining the temperature at 37 °C. Titrate with 0.1 M sodium hydroxide. This is a potentiometric titration. So nitrate till a pH of 3.5 is obtained.

Result:- Based on the above observation, one of the two reports may be submitted.

The sample passes the test.
Or
The sample doesn’t pass the test.

 Inorganic Chemistry Experiment No. 30

Aim:- To check the presence of iodate in potassium iodide.

Requirement:-

Chemical required:-

Theory:-The presence of iodate in potassium iodide can be done by adding dilute sulphuric acid and starch solution to an aqueous solution of the sample.

There should be no color produced. If, there is iodate, it reacts with potassium iodide in the presence of acid and liberates iodine. This will produce blue color with starch.

the presence of iodate in potassium iodide

Procedure:-

  1. Weigh1 gm. of the sample accurately in 20 ml of carbon-dioxide-free water.
  2. Add 0.3 ml of dilute sulphuric acid from a 1ml graduated pipette and one drop of iodide-free starch solution.

Observation:- one of the two observation should be there.

  1. No blue color is produced within 2 minutes
  2. Blue color is produced within 2 minutes.

Result:-

One of the two results may be reported.

  1. The sample passes the test
  2. The sample doesn’t passes the test.

Preparation Of Inorganic Pharmaceutical Preparations

 Inorganic Chemistry Experiment No. 31

AIM To prepare a pure sample of Potash Alum Crystal (Fit Kari),[K2SO4.Al2(SO4)3.24H20].

Requirement:-

Chemicals required:-Potassium sulphate, aluminum sulphate

Apparatus required:- Two beakers, china dish, funnel, funnel-stand, wash bottle, tripod stand and wire gauze

Theory:-Potash alum is prepared by dissolving an equimolar mixture of hydrated aluminum sulphate and potassium sulphate in minimum amount of water containing a little of sulphuric acid and then subjecting the resulting solution to crystallization, when octahedral crystal of potash alum separate out.

Potash Alum Crystal

Procedure:-

  1. Take a 250 ml beaker. Wash it with water and transfer 2.5 gm. of potassium sulfate crystals to it. Add to about 20 ml of water.Stirr to dissolve the crystals. Warm if required.
  2. Take the other 250 ml beaker, wash it with water and transfer 10 gm aluminum sulphate crystals to it. Add about 20 ml of water and 1ml of dilute sulphuric acid to prevent hydrolysis of aluminum sulphate. Heat for about 5 minutes. If milkness still persists, filter the solution.
  3. Mix the two solutions in a china-dish and place the china-dish on wire gauze placed over a burner. Stir the solution with a glass-rod. Concentrate the solution till the crystallization point is reached. Place the dish over a beaker containing cold water.
  4. Soon the crystals of potash alum separate out. Decant off the mother liquor and wash the crystals with a small quantity of ice-cold water.
  5. Dry the crystals by placing them in between the filter papers.

Observation:

Weight of crystals obtained.

Expected yield.

Colour of the crystals.

Shape of the crystals.

Applications

  1. Potash Alum is used in water purification, leather tanning, and fireproof textiles.
  2. It also has cosmetic uses as a deodorant, as an aftershave treatment.

Precautions

  1. Cool the solution slowly to get good crystals. Donot disturb the solution while it is octahedral in shap

 Inorganic Chemistry Experiment No. 32

Aim:- To prepare and submit Boric acid.

Requirement:-

Chemicals Required: borax, cone, sulphuric acid

Apparatus Required:-beaker, glass-rod, filter paper, spatula.

Theory:- boric acid occurs naturally in volcanic jets of steam. The crude boric acid crystallizes on cooling.Commerically, boric acid is prepared from sodium borate.

Boric acid is prepared by treating borax with nitric acid. Nitric acid is preferred to hydrochloric acid because sodium nitrate is more readily soluble than sodium chloride.

Boric acid is purified by re-dissolving the washed crystals in 200 ml of boiling distilled water.

Procedure:-

  1. Add 20 gm. of borax in 100ml of distilled water. Heat if necessary, to dissolve.
  2. Slowly add 1M of sulphuric acid(5% H2SO4) while stirring. After each addition, test the reaction mixture with pH paper.When the paper shows a strong red color, indicating excess acid, the reaction should be complete.
  3. Wash the precipitate on the filter with water till the filtrate is free from sulphate.
  4. Dry the precipitate in between the folds of filter paper.

Applications;- .

  1. It can be used as a local anti-infective agent.
  2. It can be used as a vehicle for ophthalmic solutions.
  3. It can be used as a buffer.

Result:- The crude boric acid obtained,

Inorganic Chemistry Experiment No. 33

Aim:- To prepare Ferrous sulphate from iron.

Requirement:-

Chemicals Required:- iron filings, cone. Sulphuric acid

Apparatus Required:- beaker, spatula, measuring cylinder, funnel.

Theory:-Ferrous sulphate (FeSO4.7H2O) traditionally known as green vitriol or copperas, forms beautiful blue green crystals of the monoclinic system. It is prepared by dissolving iron in excess of dilute Sulphuric acid.

Fe + H2SO4———————–FeSO4

Procedure: It is obtained by dissolving 1 gm. of iron filling in 20 ml of dilute sulphuric acid. After the effervescence ceases, the liquid if filtered, concentrated and cooled. The green crystals formed are separated by filtration at room temperature.

Applications:-

  1. It is useful in chemistry as a reducing agent and a source of ferrous ions.
  2. It can also be used as a hemanitic i.e. for promoting the formation of haemoglobin in anemias caused due to iron deficiency.
  3. Ferrous sulphate is used to purify wastes by flocculation