When a substance changes phase, the arrangement of its molecules changes, but its temperature does not change. If the new arrangement has a higher amount of thermal energy, then the substance absorbs thermal energy from its environment in order to make the phase change. If the new arrangement has a lower amount of thermal energy, the substance releases thermal energy to its environment.
Latent heat of vaporization is a physical property of a substance. It is defined as the heat required to change one mole of liquid at its boiling point under standard atmospheric pressure. It is expressed as kg/mol or kJ/kg. When a material in liquid state is given energy, it changes its phase from liquid to vapor; the energy absorbed in this process is called heat of vaporization. The heat of vaporization of water is about 2,260 kJ/kg, which is equal to 40.8 kJ/mol.
The vaporization is the opposite process of condensation. The heat of condensation is defined as the heat released when one mole of the...