Solved Heat of vaporization of water at 100 degree C and Chegg.com 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 The internal energy change (in J) when 90 g of water undergoes complete evaporation at `100^(@)C ` is ______ . (Given : `Delta H_("vap")` for water at 373 K = 41 kJ mol , `R = 8.314 JK^( 1) mol^( 1)`) What is E when 2.0 mole of liquid water vaporises at 100C? The heat of vaporisation, H vap. of water at 100C is 40.66 kJmol^ 1. Sarthaks eConnect Largest Online Education Community Vapor Pressure Springer Nature Link