Air initially at 15 bar and 50 degree C expands to a final p

Air initially at 15 bar and 50 degree C expands to a final pressure of 3 bar in an isothermal, internally reversible process. Determine the work and the heat transfer in kJ per kg. Assume that air behaves like an ideal gas.

Solution

>> As Process is Isothermal,

So, Internal Energy Change, dU = 0

and so, dQ = dW

As, W = mR(T1)*ln(P1/P2) { In Isothermal Process }

Putting Values in the equation,

=> W/m = 0.287*(273+50)*ln(15/3) = 149.20 KJ/Kg = Q/m ............ANSWER.........