Saturated water vapor at 400°F is heated at constant pressure until its volume has doubled. The gas constant, the critical pressure, and the critical temperature of ethane are R = 0.5956 psia·ft3/lbm·R, Tcr= 1164.8 R, and Pcr= 3200 psia. Use data from the steam tables.

Estimate the change in specific internal energy au and specific enthalpy h from inlet to outlet for ethylene glycol (a liquid) flowing through each of the following devices: (a) a heat exchanger where the glycol temperature increases from 20 °c to 80 °c; (b) a pump operating at about 25 °c and increasing the glycol pressure from 100 kpa to 8 mpa.