Definition - What does Critical temperature mean?
Critical temperature can be defined as the temperature of a substance at or above which the vapor of the substance cannot be liquified, irrespective of the amount of pressure applied.
It is possible to convert gas to a liquid by compressing it at a suitable temperature. However; as the temperature increases, it becomes more difficult to liquefy the gas because of the increase in the kinetic energy of the particles that make up the gas.
Trenchlesspedia explains Critical temperature
According to Gibb's Law of Equilibrium, pressure and temperature cannot be independent variables in the two-phase region where liquid and vapor co-exist. The solid, liquid, and vapor phases are separated by phase boundaries or pressure-temperature combinations where two phases can coexist. However; the liquid-vapor boundary terminates at a critical point with a critical temperature and critical pressure.
At temperatures above the critical temperature, dewpoints are observed. At temperatures below the critical temperature, the mix will split into two phases at the bubblepoint pressure. The bubblepoint, dewpoint, and single-phase regions are used to classify reservoirs.