This problem reinforces the concepts of phase equilibria for pure substances.

(a) Use steam table data to calculate the Gibbs energy of 1 kg saturated steam at 150°C, relative to steam at 150°C and 50 kPa (the reference state). Perform the calculation by plotting the volume data and graphically integrating. Express your answer in kJ. 

(b) Repeat the calculations using the tabulated enthalpies and entropies. Compare your answer to part (a).

(c) The saturated vapor from part (a) is compressed at constant T and 1/2 kg condenses. What is the total Gibbs energy of the vapor liquid mixture relative to the reference state of part (a)? What is the total Gibbs energy relative to the same reference state when the mixture is completely condensed to form saturated liquid?

(d) What is the Gibbs energy of liquid water at 600 kPa and 150°C relative to the reference state from part (a)? You may assume that the liquid is incompressible.

(e) Calculate the fugacities of water at the states given in parts (a) and (d). You may assume that f = P at 50 kPa.