Consider a rigid tank of volume 15 m^3 . This tank is connected to a steam supply line. The tank is initially evacuated. Steam at 15 bar and 280 C is now allowed to flow into tank until the pressure inside the tank reaches 15 bar. The tank is perfectly insulated. Determine a) the amount of mass of the steam flowed into tank in kg, b) the temperature of the steam in the tank in degrees Celcius. ANSWERS: 71.1 kg; 425 degrees celcius 2. Refrigerant-134a is contained in a 4 ft^33 tank at 160 lpf/in^2. At the beginning, the saturated vapour occupies a volume of 2 ft^3 and the remaining portion is filled with the saturated liquid. A valve is opened to allow escaping some saturated vapour. When the valve is closed, the volume of the liquid is 1 ft^3 . During this process, the pressure inside the tank remains constant. Determine a) the mass of the refrigerant that has escaped in lb, b) the heat transferred during this process in Btu. ANSWERS: 67.4 lb; 4835.1 Btu.