Flexi Says: The equilibrium constant (Keq) is the ratio of the mathematical product of the concentrations of the products of a reaction to the mathematical product of the concentrations of the reactants of the reaction. Each concentration is raised to the power of its coefficient in the balanced chemical equation. The units of Keq can be given by (mol/L)^delta n, where delta n is = sum of stoichiometric coefficients of products - sum of stoichiometric coefficients of reactants