5. Entropy changes in a non-ideal gas Finn qu 5.6. A gas has a molar specific heat given by cv = A + BT where A and B are constants. Show that the change in entropy per mole going from state (V1, T1) to the state (V2, T2) is ?s = A ln(T2/T1) + B(T2 - T1) + R ln(V2/V1) See section in lectures on “Entropy of an ideal gas”. Also, from the Central Equation, ds can be written as a sum of two terms, one involving du and the other dv. A glance at the result sought shows that the term involving du has to be re-cast as one involving dT before doing the integration to get ?S.