The difference between `Delta`H and `Delta`U at constant volume is equal to The difference between `DeltaH` and `Delta E` at constant voluem is equal to Delta H Vap Standard Enthalpy Of Atomization, Solution And Phase Transition Predicting the Enthalpy of Vaporization and Calculating the Entropy of Vaporization of 87 Octane Gasoline Using Vapor Pressure For water vap H = 41 kJ mol^1 at 373 K and 1 bar pressure. Assuming that water vapour Sarthaks eConnect Largest Online Education Community