Define critical temperature, critical pressure and critical volume.

Explanation

Critical temperature. It is the temperature of a substance in gaseous state, below which the gas can be liquified by pressure only and above which the gas can not be liquified. So a gas is simply a vapour below its critical temperature. Critical pressure. It is a pressure required to liquify a gas at its critical temperature.Critical volume. It is the volume occupied by one gm of gaseous substance at critical temperature and critical pressure