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A frictionless piston-cylinder device is filled with helium gas at 300 kPa and 40 °C. A...

A frictionless piston-cylinder device is filled with helium gas at 300 kPa and 40 °C. A thermal reservoir at 95 °C is used to heat the gas at constant pressure to a final temperature of 75 °C.

a) Determine the change in entropy per unit mass for the gas during this process. Prove your answers to

b) and c) below quantitatively using entropy concepts or briefly describe why you’re unable to evaluate.

b) Is this process internally reversible, irreversible, impossible, or you’re unable to evaluate?

c) Is this process externally reversible, irreversible, impossible, or you’re unable to evaluate?

Engineering   Mechanical-Engineering   
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Answer #1

b) Is this process internally reversible, irreversible, impossible, or you’re unable to evaluate?

Ans: The Process is Internally Reversible because there is no source of entropy generation within the system.

c) Is this process externally reversible, irreversible, impossible, or you’re unable to evaluate?

Ans: The process is externally Irreversible because there is heat transfer between reserviour and system (helium gas). Heat trasnfer with finite temperature difference generate entropy

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