NEET Chemistry Chapter 1 Matter In Our Surrounding Question And Answers
Question 1. Why does the aroma of coffee spread very fast?
Answer:
The gases have very fast rate of diffusion and therefore, the aroma of coffee spread very fast.
Question 2. Which property of gas is used in supplying oxygen cylinders to hospitals?
Answer:
Due to high compressibility of gases, oxygen cylinders are supplied to hospitals.
Question 3. What is common among the three states of matter? Why do the states of matter differ?
Answer:
The common thing among all the states of matter is that they all are made up of tiny particles which can be atoms, molecules or ions. The states of matter differ in the motion of these particles and the spaces they have in between.
Question 4. Separate the following substances in groups of high and low intermolecular force. Ice, Sulphur vapour, Nitrogen, Sugar, Copper, Air, Salt and Plastic.
Answer:
- High Intermolecular Force: Ice, Sugar, Copper, Salt, Plastic
- Low Intermolecular Forces: Sulphur vapour, Nitrogen, Air
Question 5. What do you understand by Brownian motion?
Answer:
Brownian motion
Brownian motion is the random movement of particles suspended in a fluid (liquid or gas) resulting from their collision with the fast-moving atoms or molecules in the gas or liquid.
Question 6. What is the reason of leaving a small gap at the joint of two rails?
Answer:
Reason behind the leaving a small gap at the joint of two rails is
With increase in temperature any matter will expand as heat moves the particle apart. So with increase in heat the rail track also expands. If the gap is not kept the rails will bend due to expansion making the track unusable.
Question 7. What is dry ice?
Answer:
Dry ice
When carbon dioxide is turned into solid at high pressure, it is called dry ice.
Question 8. Under what conditions can the gases be liquified? In which form is LPG filled in a gas cylinder?
Answer:
By increasing the pressure, gases can be liquified. LPG is packed into cylinders in liquid state.
Question 9. Why to steam causes more severe burns?
Answer:
Steam causes more severe burns than boiling water because it has more heat energy than water due to its latent heat of vaporization.
Question 10. What are the factors that are responsible in bringing out the change in states of matter?
Answer”
Temperature and Pressure are the two factors which are responsible to bring out the change in the state of matter.
Question 11. The average body temperature of a man is 98.5 °F. What is this temperature in Celsius?
Answer:
The formula needed to convert Fahrenheit to Celsius is:
°C = \(\frac{5}{9}\left({ }^{\circ} \mathrm{F}-32\right)\)
Where °F and °C are the temperatures in Fahrenheit and Celsius respectively
Put 99.5 °F into the formula
°C = \(\frac{5}{9}(99.5-32)\)
°C = \(\frac{5}{9}(67.5)\)
°C = 37.5 °C
The average body temperature of a man in Celsius is 37.5 °C.
Question 12. What is the latent heat of vaporization of water?
Answer: The latent heat of vaporization of water is 22.5 × 105 Joules per kilogram
Question 13. What do you understand by specific latent heat?
Answer:
Specific latent heat
The heat energy required to boil or melt a substance is known as specific latent heat of that substance.
Question 14. What is latent heat of vaporization?
Answer:
Latent heat of vaporization
The amount of heat energy that is required to change 1 kg of solid into liquid at atmospheric pressure at its melting point is called latent heat of vaporization.
Question 15. What do you understand by evaporation?
Answer:
Evaporation
It is a phenomenon of changing liquid into vapour at any temperature below its boiling point, i.e., water changes from a liquid to a gas or vapour form.
Question 16. What is latent heat?
Answer:
Latent heat
When the water is vaporised from the surface, it needs energy to convert from a liquid state to a gaseous state. The water absorbs this heat energy from the environment. This energy does not heat the water but is used in converting from liquid to gas. This heat is called Latent heat.