One kg of water vapor contained within a piston-cylinder assembly, initially at 7 bar, 320 °C, undergoes an adiabatic expansion to a state where pressure is 1.5 bar and the temperature is (a) 240°C, (b) 120°C. Using the entropy balance, determine the nature of the process in each case.

Air within a piston–cylinder assembly, initially at 50 lbf/ in.2, 510°R, and a volume of 6 ft3, is compressed isentropically to a final volume of 0.5 ft3. Assuming the ideal gas model with k = 1.4 for the air, determine the: (a) mass, in lb. (b) final pressure, in lbf/in.2(c) final temperature, in °R.(d) work, in Btu.

A rigid, well-insulated tank contains a two-phase mixture of ammonia with 0.0022 ft³ of saturated liquid and 1.5 ft3 of saturated vapor, initially at p₁ = 70 lb/in². A paddle wheel stirs the mixture until only saturated vapor at higher pressure, p2, remains in the tank. Kinetic and potential energy effects are negligible. Determine the pressure p2, in lb/in², and the amount of energy transfer by work, in Btu. Step 1 * Your answer is incorrect. Determine p2, in lb/in². P2= i81.56 lb/in²

An ideal gas initially at 70 °C and 1 bar undergoes the following reversible processes, completing a cycle. 1-2: the gas is compressed adiabatically to 150 °C. 2-3: it is then cooled at constant pressure from 150 °C to 70 °C. 3-1: finally, the gas is expanded isothermally to a final pressure at 1 bar. Take Cp 1.005 kJ/g K, Cv= 0.705 kJ/g K. Sketch the cycle P-V diagram for the entire cycle. Calculate W,Q and Au for the entire cycle.