Heating Curve Standard enthalpy of vaporisation`DeltaV_(vap).H^(Theta)` for water at `100^(@)C`is`40.66kJmol^( 1)`.Teh internal energy of Vaporization of water at` 100^(@)C("in kJ mol"^( 1))`is Latent Heat of Vaporization Delta Hvap of Water calculated by corresponding states correlation in a one cell excel formula Chem Eng Musings Vapor Pressure The enthalpy of vaporisation of water at `100^(@)C` is `40.63 KJ mol^( 1)`. The value `Delta E` for the process would be : Simple, Quick, and Accurate Determination of the Heat of Vaporization of Water Chemical Education Xchange