Thermochemical equilibrium

Thermochemical equilibrium requires every chemical reaction to have zero Gibbs free-energy change. For ideal reactants, the equilibrium constant is $K=\exp [-{\Delta }_r{G}^{\circ }/(RT)]$ after standard-state activity factors are included.

For an elementary reversible reaction, detailed balance gives $k_f{\prod }_r{n}_r^{{\nu }_r}=k_r{\prod }_p{n}_p^{{\nu }_p}$ at equilibrium. Hence the reverse rate coefficient is the forward coefficient divided by the equilibrium constant, with units fixed by the reaction stoichiometry.