A piston-cylinder device initially contains 1.4-kg saturated liquid water at 200 C. Now heat is transferred to the water until the volume quadruples and the cylinder contains saturated vapour only. Determine: (a) the volume of the tank, -> Use P1 = P2 to solve -> find Vg at 200oC (b) the final temperature and the pressure, and P2 does not equal P1. Why? I already have the solution for the above problem but I would like to know why for part b we don't have the final pressure = initial pressure. I thought that all piston cylinder devices undergo isobaric processes. Thanks in advance guys!