The equilibrium constant (Keq) is a measure of the ratio of the concentrations of products to reactants at equilibrium for a reversible chemical reaction. It is given by the formula:
\[ \text{Keq} = \frac{[\text{Products}]}{[\text{Reactants}]} \]
Consider a reaction where the concentration of products is 0.5 M and the concentration of reactants is 0.2 M:
Using the formula:
\[ \text{Keq} = \frac{0.5}{0.2} = 2.5 \]
This means the equilibrium constant is 2.5.