A rigid, well-insulated tank contains a two-phase mixture of ammonia with 0.0025 ft of saturated 3 liquid and 1.5 ft of saturated vapor, initially at . A paddle wheel stirs the mixture until only saturated 3 40 psia vapor at higher pressure remains in the tank. Kinetic and potential energy effects are negligible. For the ammonia, determine the amount of energy transfer by work.