ABSTRACT
The importance of the knowledge of standard reactional Gibbs energies is, among other reasons, justified by the fact that it permits to calculate the equilibrium constant values of chemical reactions. That is to say, they permit to foresee the concentrations of the products and reactants of a chemical or biochemical reaction at equilibrium. Hence, it is interesting to investigate some means of their obtention. The converse is also true. They are empirical methods of correlation which permit to estimate thermodynamic properties permitting, in turn, to calculate standard reaction Gibbs energies and the corresponding equilibrium constants. They also permit to estimate some enthalpies. These methods are based on “extrathermodynamic” relationships. Hence, in the physico-chemical literature, there exist numerous linear quantitative relationships between a molar property of an organic molecule and the number and the nature of the chemical groups constituting it.
