The difference between `Delta`H and `Delta`U at constant volume is equal to 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 Delta H^0 vap of water is +40.79 kJ mol at 1 bar and 100 deg C. Change in internal energy for this__ 3. (a) Derive the integrated form of Clausius Clapeyron Chapter 10: Thermochemistry Lecture Note Edubirdie