What does the Gibbs free energy change indicate about a reaction?

The Gibbs free energy change is a critical thermodynamic quantity that provides insights into the spontaneity and equilibrium of a reaction. When the Gibbs free energy change is negative, it indicates that the reaction is thermodynamically favorable and can proceed spontaneously in the forward direction. Conversely, if the change is positive, the reaction is non-spontaneous under the given conditions.

At equilibrium, the Gibbs free energy change is zero, which means that the forward and reverse reactions occur at equal rates, and there is no net change in the concentrations of reactants and products. By analyzing the Gibbs free energy, one can predict the position of equilibrium and understand how factors such as temperature and pressure influence the reaction's favorability. This predictive nature of Gibbs free energy concerning equilibrium points is pivotal in chemical thermodynamics.