Question

On the basis of kinetic theory of gases, the gas exerts pressure because its molecules

• A. suffer a change in momentum when impinging on the walls of the container.
• B. continuously stick to the walls of the container.
• C. continuously lose their energy till it reaches the wall.
• D. are attracted by the walls of the container.

Answer 1

The correct option is A

suffer a change in momentum when impinging on the walls of the container.

The explanation for the correct option

In the case of option A,

1. Kinetic theory of gas is a theoretical model that explains the molecular composition of gas in terms of a large number of ultra-microscopic particles containing atoms and molecules.
2. The theory further explains that gas pressure is generated when particles collide with each other or collide with the wall of a container.
3. According to the Kinetic theory of gas's assumption, gas molecules collide with the wall and change their momentum, applying force to the wall and creating pressure.

The explanation for the correct option

In the case of option B,

1. The gas molecules are constantly moving randomly, colliding with each other and colliding with the walls of the container.
2. When a gas molecule hits the wall of the container, there is a change in momentum.
3. The gas molecules do not stick to the wall continuously.

In the case of option C,

1. The average kinetic energy of gas molecules is directly proportional to the temperature, if temperature increases average kinetic energy of the gas molecules also increases.
2. As the collision is perfectly elastic there is no loss of energy.

In the case of option D,

1. Gas molecules are always in constant motion.
2. Because of free space, the particles move randomly in all possible directions not only towards the wall of the container.

Hence, option A is the correct answer.