PPT Enthalpy (H) PowerPoint Presentation, free download ID:5592552 5.4: Vapor Pressure Chemistry LibreTexts The enthalpy of vaporization of \mathrm{H}{2} \mathrm{O}(1) is x \mathrm{~kJ} \mathrm{mol} and enthalpy of formation of water vapour \mathrm{ykJ} \mathrm{mol}. Enthalpy of formation of 13.7: The Gibbs Free Energy Chemistry LibreTexts Confusion about enthalpy and when to use h = m(Cp)(delta T) Do I have to use one or the other in this case? : r thermodynamics If \Delta {H}{vap }^{\circ} for {H}{2} {O} is 44 {kJ} {mol}^{ 1}, then amount of heat required to evaporate 9 {~g} of {H}_{2} {O} is :