ALEKS Calculating Enthalpy of Vaporization from Vapor Pressure YouTube What is `Delta U` when `2.0` mole of liquid water vaporises at `100^(@)C`? The heat of vaporisation `(Delta H_("vap".))` of water at `100^(@)C` is `40.66 KJmol^( 1)`. 3 Ways to Calculate Vapor Pressure wikiHow Law of Equipartition of Energy Energy is equally distributed among all degrees of freedom Each degree contributes kT per molecule Translational, rotational, Standard enthalpy of vaporization (vapH) for water at 100C is 40.66 kJ.. DeltaH` (vap) for water is `40.7 kJ mol^( 1)`. The entropy of vapourisation of water is