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A piston/cylinder contains 2kg water at 200°C, 10 MPa. The water expands in an isothermal process to a pressure of 200 kPa. Any heat transfer takes place with an ambient at 200°C and whole process is be assumed reversible. Calculate the total work.

A piston/cylinder contains 2kg water at 200°C, 10 MPa. The water expands in an isothermal process to a pressure of 200 kPa. Any heat transfer takes place with an ambient at 200°C and whole process is be assumed reversible. Calculate the total work. Correct Answer 1290.3 kJ

State 1: v1 = 0.001148 m3/kg, u1 = 844.49 kJ/kg, s1 = 2.3178 kJ/kg K, V1 = mv1 = 0.0023 m3 State 2: v2 = 1.08034 m3/kg, u2 = 2654.4 kJ/kg, s2 = 7.5066 kJ/kg K, V2 = mv2 = 2.1607 m3 1Q2 = mT(s2 − s1) = 2 × 473.15 (7.5066 – 2.3178) = 4910 kJ 1W2 = 1Q2 – m(u2 – u1) = 1290.3 kJ.

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