1. The problem statement, all variables and given/known data Okay, so these are usually pretty easy for me to understand, but this one doesn't make sense. 10 kg of water in a piston cylinder arrangement exists as saturated liquid/vapor at 100 kPa, with a quality of 50%. It is now heated so the volume triples. The mass of the piston is such that a cylinder pressure of 200 kPa will float it. Find the final temperature and the heat transfer in the process. 2. Relevant equations v = V/m v - specific volume V - volume m - mass y = yf +xyfg 3. The attempt at a solution State 1: m1 = m2 = m = 10kg x1 = .5 ---> 2-phase mixture P1 = 100 kPa = 1 bar v1 = .0010432 m3/kg + (.5)(1.694 - .0010432) v1 = .8475 m3/kg State 2: v2 = 3*v1 = 2.5425 m3/kg P2 = 200 kPa --> pressure is constant from this point on Solutions I have found online say that the final temp is in the 800's. How is that possible? I went into my steam tables (Fundamentals of Engineering Thermodynamics, Moran) and I couldn't figure out the state. I assume it is a superheated vapour. Is this right? If so, I go to the tables and the temp could probably be interpolated between 1.5 bar and 3 bar, but even then it's not close to 800. I believe the answer is 827 or 829 degrees C. Thanks for any help.