Planet CBD Standard enthalpy of vaporisation \Delta _ { v a p } H ^ { \circ } for a .. Kit cigarette lectronique Armes & Liquides Standard enthalpy of vapourisation \Delta _ { \mathrm { vap } } \mathrm {.. Delta H Vap The enthalpy of vaporisation of water at `100^(@)C` is `40.63 KJ mol^( 1)`. The value `Delta E` for the process would be : Standard enthalpy of vapourisation `Delta_("vap")H^( )` for water at `100^@C` is `40.66 kJ mol^( 1)`. The internal energy of vapourisation of water at `100^@C` (in kJ `mol^( 1)`) is (Assume water vapour to behave like