Question

Gas exerts pressure on the walls of the container because the molecules-
(A). Are losing the kinetic energy
(B). Are getting stuck to the walls
(C). Are transferring their momentum to walls
(D). Are accelerated towards walls

Answer 1

The gas molecules are very far away from each other as negligible forces exist between them. The kinetic energy of the molecules is very high and their motion is completely random. Due to their random motion, they collide with each other and with the walls of the container.

Complete answer:
In a gas the pressure is minimum out of all solids, liquids and gases and the molecules are far away from each other. The Vander-waal forces are very weak between the molecules of gas. As the forces between the molecules are very weak, the potential force is negligible but the kinetic energy of the molecules is very high.
Due to the very high kinetic energy of the molecules, they are moving randomly at very high speeds. When a gas is enclosed in a container, due to very high speeds of the molecules, they collide with the walls of the container as well as with each other. When they collide with the walls of the container, force is applied. The force applied per unit is the pressure exerted by gas molecules on the walls of the container.
The force applied is the rate of change of momentum. Therefore, we can say that molecules transfer their momentum to the walls.
Therefore, as the kinetic energy of molecules is very high, they collide with the walls of the container and exert pressure and transfer their momentum to the walls of the container.

Hence the correct option is (D).

Note:
The van der-waals forces are the force of attraction between molecules, it is the weakest force. The velocity of the molecules is taken as the root mean squared velocity. The collisions of the molecules are elastic; this means that the kinetic energy of the molecules is conserved. Force exerted by the molecules on the walls of the container is equal and opposite.