# Equilibrium constant

The equilibrium constant is the ratio of the equilibrium concentrations of the products raised to the power of their stoichiometric coefficients to the equilibrium concentrations of the reactants raised to the power of their stoichiometric coefficients. a number that expresses the relationship between the amounts of products and reactants present at equilibrium in a reversible chemical reaction at a given temperature. For a reversible reaction:

aA + bB ⇌ cC + dD

The equilibrium constant, K, is equal to

K = [C]^{c} [D]^{d} / [A]^{a} [B]^{b}

where

[A] = equilibrium concentration of A

[B] = equilibrium concentration of B

[C] = equilibrium concentration of C

[D] = equilibrium concentration of D