What is the equilibrium constant and how is it related to chemical equilibrium?

The equilibrium constant is a numerical value that expresses the ratio of product concentrations to reactant concentrations at equilibrium.

Chemical equilibrium occurs when the rate of the forward reaction is equal to the rate of the reverse reaction. At this point, the concentrations of reactants and products remain constant over time. The equilibrium constant, denoted as Kc, is a measure of the extent to which a reaction has reached equilibrium. It is calculated by dividing the product concentrations raised to their stoichiometric coefficients by the reactant concentrations raised to their stoichiometric coefficients.

Kc = [products]^(stoichiometric coefficients of products) / [reactants]^(stoichiometric coefficients of reactants)

The value of Kc is constant at a given temperature and pressure, and it is independent of the initial concentrations of reactants and products. If Kc is greater than 1, the equilibrium lies towards the products, while if Kc is less than 1, the equilibrium lies towards the reactants. If Kc is equal to 1, the reaction is said to be at equilibrium.

The equilibrium constant is an important tool in understanding chemical reactions and predicting their outcomes. It can be used to determine the direction in which a reaction will proceed, as well as the concentrations of reactants and products at equilibrium.