Air is expanded in a polytropic process with n = 1.5 from 2 MPa and 300°C to 80 kPa in a piston-cylinder device. Determine the final temperature of the air.

A 0.3m³ rigid tank initially contains saturated liquid water at 200°C. A valve at the bottom of the tank is opened until half of the mass in saturated liquid form is withdrawn from the tank. The temperature is maintained constant. Determine the amount of heat transfer during this process. Sat. liquid T = 200°C V = 0.3 m³

A 0.78 m³ tank initially contains water at 260°C and a quality of 0.81. A valve at the top of the tank is opened and allows for saturated vapor at 260°C to leave the tank. The tank is maintained isothermally during this process until the tank is filled with only saturated vapor at 260⁰ C. What is the mass of steam that leaves the tank during this process? How much heated is added to the tank during this process. KJ kg

A 0.68 m3 rigid tank contains refrigerant-134a initially at 100 kPa and 40 percent quality. Heat is now transferred to the refrigerant until the pressure reaches 400 kPa. Determine:   Final temperature the mass of the refrigerant in the tank the amount of heat transferred.