# Physical Chemistry Questions and Answers – Kinetic Gas Theory

This set of Physical Chemistry Multiple Choice Questions & Answers (MCQs) focuses on “Kinetic Gas Theory”.

1. What is Mean free path?
a) Average distance of a molecule can travel without colliding
b) Average distance of molecule can travel with colliding
c) A thermodynamic potential used to calculate the maximum of reversible work
d) It determines whether a chemical reaction is spontaneous or not

Explanation: It is the average distance traveled by a moving particle between successive collisions, which modify its direction.

2. In dynamic equilibrium, molecules collide and change their speeds during collisions.
a) False
b) True

Explanation: A dynamic equilibrium exists once a reversible reaction ceases to change its ratio of reactants or products, but substances move at an equal rate.

3. What is Boyle’s law?
a) the volume of an ideal gas at constant pressure is directly proportional to the absolute temperature
b) This law states that pressure of a given mass of an ideal gas is inversely proportional to its volume
c) Energy is equally distributed to all energy modes, with each mode having an average equal to KBT
d) This law states that pressure exerted on the sides of the container is directly proportional to its absolute temperature

Explanation: Boyle’s law is shows how pressure of a gas tends to increase as the volume of the container decreases.

4. Kinetic theory of an ideal gas gives the relation P1/3nv2.
a) False
b) True

Explanation: Kinetic gas theory gives the relation P1/3nmv2 where n is number density of molecules, m is the mass of the molecule and v2 is mean of square speed.

5. Which one of these is correct for Translational kinetic energy?
a) E = 1/3 nmv2
b) E = 1/3 KB N T
c) E = 3/2 KB N T
d) E = 3/2 nmv2

Explanation: Translational motion is the motion along a line or in the space. So, the kinetic energy possessed by the body or the object through its translational motion is called translational kinetic energy.

6. What is the specific heat of a gas in isothermal process?
a) Negative
b) Remains constant
c) Infinite
d) Zero

Explanation: The specific heat of a gas in isothermal gas in infinite. The heat supplied is compensated by P-V work done, then the temperature will not increase. So, ΔT=0. Then, C=∞.

7. What is the latent heat of ice?
a) More than external latent heat of fusion
b) Twice the external latent heat of fusion
c) Less than external latent heat of fusion
d) Equal to the external latent heat of fusion

Explanation: The difference in enthalpies comes from the fact that a liquid molecule is stabilized by interactions with other nearby molecules (therefore a small heat of fusion) and a gas has very little intermolecular stabilization.

8. The specific heat of a substance at its boiling point or melting point:
a) Lies between 0 and 1
b) Infinite
c) Negative
d) Zero

Explanation: The specific heat is infinite because there is no temperature change because no water turns into steam.

9. What is the specific heat of water?
a) 6.989 joule/gram ℃
b) 9.875 joule/gram ℃
c) 1.142 joule/gram ℃
d) 4.186 joule/gram ℃

Explanation: The specific heat of water is 1 calorie/gram = 4.186 joule/gram ℃ which is higher than any other substance.

10. Which energy is required to convert substance from solid to liquid state at its melting point?
a) Solidification
b) Latent heat of fusion
c) Evaporation
d) Latent heat of fission

Explanation: The heat energy required for completely changing 1 kg of a solid into liquid state at atmospheric pressure.

Sanfoundry Global Education & Learning Series – Physical Chemistry.

To practice all areas of Physical Chemistry, here is complete set of Multiple Choice Questions and Answers.

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