7. At 1 bar pressure, water boils at 373 K with vapHo (373 K) = 40.7 kJ mol-1. A kettle containing 500g of boiling water is heated until evaporation is complete. Assuming that steam behaves as an ideal gas and that liquid water is of negligible volume, calculate: (a) the volume change, (b) the work done by the water, (c) the heat put into the water, (d) U, (e) H for the process.