Question

A liquid is in equilibrium with its vapour in a sealed container at a fixed temperature. The volume of the container is suddenly increased.What happens when equilibrium is restored finally and what will be the final vapour pressure?

Answer 1

We know that a Vapour pressure is the pressure exerted by the vapor in equilibrium with the liquid at a fixed temperature.

When equilibrium is restored finally, then the rate of evaporation becomes equal to the rate of condensation.

Here, only the volume changes while the temperature remains constant.

The vapour pressure depends on temperature and not on volume.

Hence, the final vapour pressure will be equal to the first vapour pressure of the system.