Question

A gas exerts pressure on the walls of the container ,give reason

Answer 1

The molecules are continually colliding with each other and with the walls of the container. When a molecule collides with the wall, they exert small force on the wall The pressure exerted by the gas is due to the sum of all these collision forces.The more particles that hit the walls, the higher the pressure.

Answer 2

As gas has no fixed volume and shape so its particles are continuosly in motion and keeps on colliding with the walls of the container. When a particle hit wall it exert small pressure on the wall of container. When the collision force exerted by all the particles of gas then the pressure increases. This is how gas exerts pressure on walls of container.