The infinitesimal heat transfer δQ is expressed as a function of the state variables T and V in equation (5.4). It was done as a function of the state variables T and p in equation (5.17). Express the infinitesimal heat transfer δQ as a function of V and p.
δQ = T dS(T, V) ≡ C_V (T, V) dT + L_V (T, V) dV .
δQ = T dS(T, p) ≡ C_p (T, p) dT + L_p (T, p) dp .