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## Main Question or Discussion Point

Im studying for the Fundamentals of Engineering exam (coming up April 12!!) and came across this Thermodynamics problem in my review book.

In the solution to the problem, the

Is this solution wrong? As I see it, this cant be solved without knowing the number of moles of gas (or mass of the gas depending on which

So the work for an isothermal process isA gas goes through the following processes:

A to B: isothermal compression

B to C: isochoric compression

C to A: isobaric expansion

P_{C}= P_{A}= 1.4bar

V_{C}= V_{B}= 0.028m^{3}

The net work during the C-to-A process is W_{CA}= 10.5kJ

What work is performed in the A-to-B process?

*RT*), where_{A}*ln(V_{B}/V_{A}*V*was previously determined to be_{A}*0.103m*.^{3}In the solution to the problem, the

*RT*term is replaced with_{A}*P*, where it should be_{A}*V_{A}*(P*from the ideal gas law._{A}*V_{A})/nIs this solution wrong? As I see it, this cant be solved without knowing the number of moles of gas (or mass of the gas depending on which

*R*is used). I was unable to get the correct answer, and the solution seems wrong to me.