If Kc < 1, which statement best describes the equilibrium?

If Kc < 1, which statement best describes the equilibrium?

• A. Products are favored at equilibrium
• B. The reaction goes to completion
• C. Equilibrium strongly favors products
• D. Reactants are favored at equilibrium

Answer: (D)

The equilibrium constant Kc shows how the concentrations of products compare to reactants at equilibrium. If Kc is less than 1, the denominator (reactants) dominates the ratio, so the concentrations of products are smaller than those of reactants at equilibrium. This means the system lies toward the reactants, i.e., reactants are favored at equilibrium. It doesn’t mean the reaction goes to completion; some product is still formed, but the equilibrium position sits to the left. Only when Kc is much greater than 1 would products be favored, approaching completion.

The equilibrium constant Kc shows how the concentrations of products compare to reactants at equilibrium. If Kc is less than 1, the denominator (reactants) dominates the ratio, so the concentrations of products are smaller than those of reactants at equilibrium. This means the system lies toward the reactants, i.e., reactants are favored at equilibrium. It doesn’t mean the reaction goes to completion; some product is still formed, but the equilibrium position sits to the left. Only when Kc is much greater than 1 would products be favored, approaching completion.