5.4: Vapor Pressure Chemistry LibreTexts Video answer for \Delta_{\text {vap }} \mathrm{H}^{\Theta} for water is +40.79 \mathrm{kJ} \mathrm{mol}^{ 1} at 1 bar and 100^{\circ} \mathrm{C}. Change in internal energy for this vapourisation under 5) For vaporization of water at 1 bar, \Delta H = 40.63 \mathrm {kJ} \ma.. Latent Heat of Vaporization Delta Hvap of Water calculated by corresponding states correlation in a one cell excel formula Chem Eng Musings Hvap for water is 40.7 KJ `mol^(1)` . The entropy of vaporization of water is: CHAPTER 8