The entropy of water at atmospheric pressure and 100 degree C is 0.31 cal/g K, and the entropy of steam at the same temperature and pressure is 1.76 cal/g.K. (a) What is the heat of vaporization at this temperature? (b) The enthalpy of steam under these conditions is 640 cal/g. please calculate the enthalpy of water under these conditions. (c) Calculate the Gibbs energy of water and steam under these conditions. (d) Prove that the Gibbs energy function does not change in a reversible isothermal isobaric process.