Hi, I found a derivation for heat transfer in a constant pressure process. It goes as follows:(adsbygoogle = window.adsbygoogle || []).push({});

Q + W = u_{2}- u_{1}

Q = u_{2}- u_{1}+ p(v_{2}- v_{1})

Since h = u + pv, Then

Q = h_{2}- h_{1}

The first equation states that the sum of heat and work done is equal to the change in internal energy, I can comprehend up to there. But in the next line the work done is taken to the other side of the equation; both mathematically and physically I cannot understand how the work done (p(v_{2}- v_{1})) is still positive.

Mathematically I would say that taking work to the opposite side would make work negative.

Physically I would think that the amount of heat supplied/given off would be equal to the difference of initial and final internal energy minus the work done.

Hope someone could clear this out for me. Thanks

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# Thermodynamics Constant Pressure Process

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