Gibbs–Helmholtz equation and entropy

This short paper deals with the close relation of the Gibbs–Helmholtz (G–H) equation to entropy. It is shown that the G–H equation is readily derived from the entropy equivalent of the Gibbs function, the Massieu function. This derivation is also compared to another simple and straightforward derivation which uses mostly pure mathematical operations for multivariate functions, without revoking the Massieu function. Finally, the so-called “compensation effect” is also treated in some detail, citing a critical paper which testifies that this effect is an artefact; it simply reflects the relation between the Gibbs function, the enthalpy, and the entropy.