Calculate the equilibrium constant from equilibrium concentrations.
Concentrations are raised to their stoichiometric coefficients, which is why K is so sensitive to coefficients. A K above one means products dominate at equilibrium, and the free energy change follows directly. K is temperature dependent but concentration independent, which is what makes it a genuine constant rather than a measured ratio.
Equilibrium Constant
K = [products]^coefficients ÷ [reactants]^coefficients; ΔG° = −RT ln K
K = [products]^coefficients ÷ [reactants]^coefficients; ΔG° = −RT ln K Concentrations are raised to their stoichiometric coefficients, which is why K is so sensitive to coefficients. A K above one means products dominate at equilibrium, and the free energy change follows directly.
K is temperature dependent but concentration independent, which is what makes it a genuine constant rather than a measured ratio.
This calculator takes 5 inputs: Product A concentration, Coefficient of product A, Reactant B concentration, Coefficient of reactant B, Reactant C concentration. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.