Other useful relations discussed in this page include the TdS equations, multiple equations relating specific heats to other thermodynamic variables (U, H, V, P, and T), and the Gibbs-Helmholtz Relati...Other useful relations discussed in this page include the TdS equations, multiple equations relating specific heats to other thermodynamic variables (U, H, V, P, and T), and the Gibbs-Helmholtz Relation.