1.5-ibm of water at 350 psia fill a weighted piston-cylinder device whose volume is 1 ft. the water is then heated at constant pressure until the temperature reaches 550°f. determine the resulting change in the water's total entropy. problem 4 refrigerant-134a at 280 kpa and 50°c undergoes an isothermal process in a closed system until its quality is 40 percent. on per unit mass basis, determine how much work and heat transfer are required.