1. Carbon dioxide (CO2) gas undergoes a process in a well-insulated piston-cylinder assembly from P1 = 2 bar, T1 = 300 K to P2 = 20 bar, T2 = 1700 K. Assuming this CO2 behaves like an ideal gas: (a) What is the intensive entropy change using a constant, average value for heat capacity that represents the relevant range of process conditions? (b) What is the intensive entropy change accounting for the change of specific heat with temperature? (c) what is the percent difference between results using the different models? (d) which of these is most accurate, why? (e) for case (b), what is the entropy generation for this process? 2. A steady-flow turbine running on air working fluid has P1 = 8 bar, T1 = 1400 K at the inlet and the air expands to P2 = 0.8 bar at the turbine exit. Assume there is no heat loss, no significant KE and PE effects and accounting for temperature effects of heat capacity. Under these assumptions, what is the theoretical limit for the intensive work involved in this turbine process if the air behaves like an ideal gas? 3. Nitrogen is flowing at steady state through a well-insulated diffuser with inlet conditions of P1 = 0.656 bar, T1 = 300 K and = 292 m/s. The exit conditions of the nitrogen flow are P2 = 0.9 bar and 2 = 130 m/s. The inlet area is A1 = 4.8 x 10- m. (a) What is the extensive entropy change rate (kJ/K/s) for the process using cold air standard assumptions? (b) What is the area at the exit assuming cold air standard assumptions?