1. A piston/cylinder contains 0.25 kg of R-134a at 100 kPa. It will be compressed in an adiabatic reversible process to 400 kPa and should be at 70?C. What should the initial temperature be?
2. A piston/cylinder contains 0.5 kg of water at 200 kPa, 300?C, and it now cools to 150?C in an isobaric process. The heat goes into a heat engine that rejects heat to the ambient at 25?C (shown in Fig. P6.46), and the whole process is assumed to be reversible. Find the heat transfer out of the water and the work given out by the heat engine.