Question

XPLAIN WHY ABOVE THE CRITICAL TEMPERATURE GASES CANNOT BE LIQUIFIED EVEN APPLYING ENORMOUS PRESSURE??

Answer 1

Dear student!
Generally, ​when pressure is increased, the volume is decreased (following PV = nRT) and so the gas particles come closer and so they loose their energy and the intermolecular force of attraction starts to work which makes a loose bonding between the molecules and the gas becomes liquefied.
But, at the critical temperature, it is that temperature where the gases and its liquid forms coexist so that they have similar properties and gases can not be identifed either in vapor or in liquid forms and so even on applying huge pressure we can not liquefy the gases above their critical temperature. As, at this temperature the volume does not changes or it maintains an equilibrium due to which no identification is possible between the liquid and vapour states.