Cp - Cv for a real gas I am trying found a relation between cp - cv for a real gas. I know how to calculate for an ideal gas, but when I try to do the same for a real gas I stopped at some point and I don't know how to continue.
The EOS used is Van der Waals equation.
If someone could help me, please, I am glad for it.
You need to show that $$\left(\frac{\partial U}{\partial V}\right)_T=-P+T\left(\frac{\partial P}{\partial T}\right)_V$$