Question

Which of the following is not a correct postulate of kinetic theory of gases?

• A. The molecules of a gas are continuously moving in different directions with different velocities.
• B. The average kinetic energy of the gas molecules is directly proportional to the absolute temperature of the gas.
• C. The volume of the gas is due to the large number of molecules present in it.
• D. The pressure of the gas is due to the collision of the molecules on the walls of the container.

Answer 1

Answer: (C)

The volume of the gas is due to the large number of molecules present in it.

KINETIC THEORY OF GASES
(a) All the gases consists of very small molecules or atoms whose volume is negligible compared to volume of container (in case volume of container is very small, then this assumption will be violated)
(b)There is no interaction between gaseous particles (the interaction may appreciably affected under certain conditions of temperature and pressure).
(c)The gaseous molecules are under a continuous state of motion which is unaffected by gravity (the random straight line motion is known as brownian motion)
(d)Due to the continuous motion, collision between gaseous molecules with the wall of container occurs. The collision with the wall of container are responsible for pressure exerted by the gas on the wall of container.
(e)The molecule moves with different speed, however the speed of each molecule keep on changing as the collision occur.
(f)All the collision occurring are considered to be perfectly elastic which implies that there is no loss of energy.
(g)The average kinetic energy of gas will depends on absolute temperature only.