One-quarter lbmol of oxygen gas (O2) undergoes a process from p1 = 20 lbf/in2, T1 = 500oR to p2 = 150 lbf/in2. For the process W = -500 Btu and Q = -140.0 Btu. Assume the oxygen behaves as an ideal gas.  Determine T2, in oR, and the change in entropy, in Btu/oR.

Consider a turbine operating at steady-state with the operating conditions shown in the figure. Superheated water vapor enters the turbine with a mass flow rate of m = 5 and superheated water vapor exits at p2 and T2. Ignoring stray heat transfer and kinetic and potential effects: a. Calculate the net power of the turbine, Wr, in kW b. Calculate the entropy produced in kW/K All state properties needed to solve are provided below: State T (°C) p (bar) h (kJ/kg) s (kJ/kg-K) (1 1 240 10 2920.4 6.8817 Wr 2 160 3 2782.3 7.1276 P1 = 10 bar T = 240 °C = 3 bar (2) P2 T2 = 160 °C

1. thermodynamics

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