The heat of vaporization (also known as enthalpy of vaporization) is the amount of energy required to convert a unit mass of a substance from liquid to vapor at constant temperature and pressure.
The formula for calculating the heat of vaporization () is:
Where:
- is the heat of vaporization (in joules per kilogram or J/kg)
- is the amount of heat absorbed during vaporization (in joules or J)
- is the mass of the substance vaporized (in kilograms or kg)
The SI unit for the heat of vaporization is joules per kilogram (J/kg). This means it’s the amount of energy required to vaporize one kilogram of the substance.