Ammonia in a piston–cylinder assembly undergoes two processes in series. initially, the ammonia is saturated vapor at p1 5 100 lbf/in.2 process 1–2 involves cooling at constant pressure until x2 5 75%. the second process, from state 2 to state 3, involves heating at constant volume until x3 5 100%. kinetic and potential energy effects are negligible. for 1.2 lb of ammonia, determine (a) the heat transfer and work for process 1–2 and (b) the heat transfer for process 2–3, all in btu.