Equivalent to Heat required to vaporize one mole of a substance at its boiling point under standard pressure (101,325 Pa). The heat of vaporization is expressed in kJ/mol., and Heat absorbed or released as the result of a phase change. There are three basic types of latent heat each associated with a different pair of phases: fusion (solid-liquid), vaporization (liquid-gas), and sublimation (solid-gas). No temperature change occurs during a phase change, thus there is no change in the kinetic of a substance. It is the amount of heat that must be removed from one gram of a vapor at its condensation point to condense the vapor with no change in temperature.