1. A hydrogen gas in a piston/cylinder assembly at 300 K, 100 kPa with a volume of 0.1 m3 is now slowly compressed to a volume of 0.01 m3 while cooling in a reversible isothermal process. What is the final pressure, the heat transfer, and the change in entropy?
2. A rigid tank contains 4 kg air at 300?C, 4 MPa that acts as the hot energy reservoir for a heat engine with its cold side at 20?C, shown in Fig. P6.99. Heat transfer to the heat engine cools the air down in a reversible process to a final 20?C and then stops. Find the final air pressure and the work output of the heat engine.
