A frictionless piston-cylinder device contains a saturated liquid-vapor mixture of water at 400K. During a constant pressure, process, 960 kJ of heat is transferred to the surrounding air at 300K. As a result, part of the water vapor contained in the cylinder condenses. Determine the entropy change of the surrounding air in kJ/K.

2. 2 kg of water in a piston-cylinder assembly undergoes two consecutive reversible processes: a. Process 1-2: Isentropic compression from P1 = 0.1 MPa, T1=100°C to P2=D0.5 MPa b. Process 2-3: Isobaric process to a temperature T3 = 400 C Determine heat transfer (kJ), work (kJ), and change in specific entropy (kJ/kgK) for each process.

A vessel initially contains 5.0 kg of liquid water and 2.0 kg of ice at 0°C. Energy is added until the ice has just melted. The temperature at the boundary where heat transfer occurs is taken to be the system temperature during the process. The enthalpy of melting is 333.5 kJ/kg. Consider the following processes used to melt the ice. a. Heat is added from the environment at 20°C. Determine the entropy flux and the total entropy generation, both in kJ/K. b. Heat is added from a reservoir at 727°C. Determine the same quantities as in part (a). c. Paddle-wheel work is used to change the state. Determine the total entropy production for the process, in kJ/K. d. Comment on the relative degree of irreversibility for the three processes.

A rigid cylindrical tank stores 80 kg of a substance at 400 kPa and 480 K while the outside temperature is 290 K. A paddle wheel stirs the system transferring shaft work at a rate of 0.7 kW. At the same time an internal electrical resistance heater transfers electricity at the rate of 1.6 kW. A. Do an energy analysis to determine the rate of heat transfer for the tank. B. Determine the absolute value of the rate at which entropy leaves the internal system (at a uniform temperature of 480 K). Answer in kW/K C. Determine the rate of entropy increase in the system's surroundings. Answer in kW/K