If the equilibrium constant K for a reaction at a given temperature is much greater than 1, what does this imply about the position of equilibrium?

• A. The products are favored at equilibrium.
• B. The reactants are favored at equilibrium.
• C. The system is necessarily at equilibrium with K > 1.
• D. The reaction is not feasible.

Answer: (A)

When a reaction reaches equilibrium, the equilibrium constant expresses the ratio of product activities to reactant activities at that temperature. If this constant is much greater than 1, the numerator dominates, so the equilibrium mixture has far more products than reactants. That means the position of equilibrium lies toward the product side, with products being favored.

If the constant were much less than 1, reactants would be favored. The idea that the system is “necessarily at equilibrium with K > 1” is a misunderstanding—K describes the ratio at equilibrium, not a statement about the current state of a system unless it has actually reached equilibrium. And calling the reaction not feasible isn’t accurate here; a large K indicates the forward process is thermodynamically favorable (though kinetics could still affect how fast it proceeds).