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1. [2 points] Ethylene gas (C₂H4) enters a compressor operating at steady state at 310 K, 100 kPa and is compressed to 600 K, 500 kPa. Assuming the ideal gas model, determine the change inspecific entropy of the gas from inlet to exit, in kJ/kg.k. 2. [3 points] A steam turbine operates at steady state with inlet conditions of p₁ = 500 kPa,T₁ = 320°C. Steam leaves the turbine at a pressure of 100 kPa. There is no significant heat transfer between the turbine and its surroundings, and kinetic and potential energy changes between inlet and exit are negligible. If the isentropic turbine efficiency is 75%, determine the work developed per unit mass of steam flowing through the turbine. 3. [5 points] Air at 400 kPa, 970 K enters a turbine operating at steady state and exits at 100 kPa,670 K. Heat transfer from the turbine occurs at an average outer surface temperature of 315 K at the rate of 30 kJ per kg of air flowing. Kinetic and potential energy effects are negligible. For air as an ideal gas with Cp‚ = 1.1 kJ/kg.K, determine (a) the rate power is developed, in kJ per kg of air flowing, and (b) the rate of entropy production within the turbine, in kJ/K per kg of air flowing.

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