5. A rigid tank initially contains 10 kg O2 at 200 kPa and 600 K. Now O2 is gradually cooled under constant volume until its temperature reaches 455 K. (18 Points) (b) Determine the boundary work. (6 points) (a) Calculate the pressure of O2 at final state. (4 points) (b) Calculate the heat transfer during this process. (8 Points)

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