Free-energy relationship

In physical organic chemistry, a free-energy relationship or linear Gibbs energy relation relates the logarithm of a reaction rate constant or equilibrium constant for one series of reactions with the logarithm of the rate or equilibrium constant for a related series of reactions. Establishing free-energy relationships helps understanding the reaction mechanism for a chemical reaction and makes it possible to predict reaction rates and equilibrium constants.

Additional recommended knowledge

Weighing the right way

Recognize and detect the effects of electrostatic charges on your balance

Daily Visual Balance Check

The Brønsted catalysis equation describes the relationship between the ionization constant of a series of catalysts and the reaction rate constant for a reaction on which the catalyst operates. The Hammett equation predicts the equilibrium constant or reaction rate of a reaction from a substituent constant and a reaction type constant. The Edwards equation relates the nucleophilic power to polarisability and basicity.