Question

Gase having high and low critical temperature

Answer 1

Gases become more difficult to liquefy as the temperature increases because the kinetic energies of the particles that make up the gas also increase. The critical temperature of a substance is the temperature at and above which vapor of the substance cannot be liquefied, no matter how much pressure is applied.

Answer 2

We previously saw that a combination of high pressure and low temperature allows gases to be liquefied. As we increase the temperature of a gas, liquefaction becomes more and more difficult because higher and higher pressures are required to overcome the increased kinetic energy of the molecules.