How much energy (in kilojoules) is released when 12.8 g of steam at 124.5 degree celcius is condensed to give liquid water at 79.5 degree celcius? The heat of vaporization of liquid water is 40.67 kJ/mol , and the molar heat capacity is 75.3 J/(K*mol) for the liquid and 33.6 J/(K*mol) for the vapor.