What is the formula for the Gibbs free energy change equation?

The Gibbs free energy change equation provides a relationship between the change in free energy of a reaction and the concentrations of the products and substrates at any given moment. The correct formula is expressed as ∆G = ∆G°' + RT ln [P]/[S].

In this equation, ∆G represents the Gibbs free energy change under non-standard conditions, ∆G°' is the standard Gibbs free energy change, R is the universal gas constant, T is the temperature in Kelvin, and [P] and [S] are the molar concentrations of products and substrates, respectively. The logarithmic term accounts for the ratio of product to substrate concentrations, indicating that as the concentration of products increases relative to substrates, the free energy change will also shift.

The use of the natural logarithm in this context reflects the thermodynamic principles governing chemical reactions—specifically, how the spontaneity and directionality of a reaction are influenced by the concentrations of reactants and products. An increase in the ratio [P]/[S] corresponds to a more favorable reaction forward, which could lower the Gibbs free energy change, while a decrease would have the opposite effect.

Understanding this formula is crucial for predicting reaction behavior in biochemical systems and interpreting metabolic