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Enthalpy of Vaporization of Water

Energy has to be added to liquid water to make it evaporate. This is the so-called enthalpy of vaporization, which can be calculated here. This energy input doesn't increase the temperature of the water (vapour).
The amount of water has to be specified in mole or as a mass. A specification as volume is not possible, because volume changes with temperature. Please enter the amount of water and the temperature of it in kelvin, degrees Celsius or Fahrenheit. The enthalpy of vaporization will be calculated in joule or kilojoule.

Amount of water:
Water temperature:
Enthalpy of vaporization:

The formula for the enthalpy of vaporization H at temperature T in kelvin is H = [50,09-0,9298*T/1000-65,19*(T/1000)²] kj/mole

Example: to evaporate one kilogram of water at a temperature of 20 degrees centigrade, an energy input of 2.454 kilojoules is needed.

The energy for vaporization can be taken from the environment, which induces evaporative cold. If e.g. one kilogram of water is cooled for 1 degree Celsius or Kelvin (1.8 degrees Fahrenheit), about 4.2 kilojoules enthalpy of vaporization will be set free.


No responsibility is taken for the correctness of this information.

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