Q-1 Complete this table for refrigerant-134a: T, C P, kPa v, m/kg Phase description -8 320 30 0.015 180 Saturated vapor 80 600 Q-2 A piston-cylinder device contains 0.85 kg of refrigerant-134a at 10C. The piston that is free to move has a mass of 12 kg and a diameter of 25 cm. The local atmospheric pressure is 88 kPa. Now, heat is transferred to refrigerant-134a until the temperature is 15C. Determine (a) the final pressure,(b) the change in the volume of the cylinder, and (c) the change in the enthalpy of the refrigerant-134a. R-134a 0.85 kg -10C Q-3 A rigid tank with a volume of 2.5 m3 contains 15 kg of saturated liquid-vapor mixture of water at 75C. Now the water is slowly heated. Determine the temperature at which the liquid in the tank is completely vaporized. Also, show the process on a T-v diagram with respect to saturation lines. HO 75C Q-4 A rigid tank contains water vapor at 250C and an unknown pressure. When the tank is cooled to 150C, the vapor starts condensing. Estimate the initial pressure in the tank. HO T= 250C P = ? Q-5 A spherical balloon with a diameter of 6 m is filled with helium at 20C and 200 kPa. Determine the mass of the helium in the balloon. He D=6m 20C 200 kPa