OK, I have a piston-cylinder with water. V = 50L = 0.05 m^3 T = 25 C P = 300 kPa m = 49.85 kg specific volume @ 25 C = 0.001003 m^3/kg The water is heated to vaporization with pressure held constant. I need to determine the final temperature and the enthalpy change. I know what the answers need to be (133.55 C and 103,627 kJ). On the temperature, I tried doing T = (PV/mR), using R = 0.4615 (kPa*m^3)/(kg*K), but i didn't get anywhere close. On the enthalpy change part, I figured using m*h_fg, but that isn't right (I think). Any ideas? Thanks a lot!!!