What is the Gibbs free energy change at equilibrium?

At equilibrium, the Gibbs free energy change is equal to zero. This is because, at this state, the forward and reverse reactions in a system occur at the same rate, leading to no net change in the concentration of reactants and products. The Gibbs free energy (G) is a thermodynamic potential that measures the maximum reversible work that can be performed by a system at constant temperature and pressure. When a system reaches equilibrium, the system has attained its lowest potential energy state, meaning that there is no further spontaneous change in the concentrations of reactants and products. Therefore, the Gibbs free energy change (ΔG) does not favor either direction of the reaction (forward or reverse), resulting in ΔG being zero. This understanding is crucial in biochemistry, especially when predicting how biochemical reactions will proceed under given conditions.