Answer to Question #154996 in General Chemistry for Rajat

Question

Pressure must be exerted on a sample of a gas in order to confine it.

Please explain.

Answer 1

For a sample of gas to be confined in a constant volume container, a constant pressure must act upon it to counteract the pressure of the gas which depends on the number of collisions its molecules have with the walls of the container.

To explain this further;

If a container is kept at a constant temperature and subjected to a regularly increasing amount of pressure. When the piston is stationary, the pressure it exerts on the gas sample is equal to the pressure the gas exerts on it. When the pressure on the piston is doubled, it moves downward until the pressure exerted by the gas equals the pressure exerted by the piston.