How can you use a balanced chemical equation to write an equilibrium constant expression?

To write an equilibrium constant expression using a balanced chemical equation, you need to identify the reactants and products involved in the equilibrium and write the expression as a ratio of the products raised to their stoichiometric coefficients divided by the reactants raised to their stoichiometric coefficients. The general format is [products]/[reactants]. The coefficients from the balanced equation become the exponents in the expression.