An equation used in thermodynamics to show the temperature dependence of the Gibbs free energy. It has the form:(∂G/∂T)p = (G − H)/T, where G is the Gibbs free energy, H is the enthalpy, T is the thermodynamic temperature, and p is the pressure (which is held constant). The Gibbs-Helmholtz equation can be derived from (∂G/∂T)p = − S and S = (H − G)T using the rules of differentiation. The equation was derived by J. W. Gibbs and H. L. F. von Helmholtz.
(∂G/∂T)p = (G − H)/T