The equilibrium constant Kc tells you the ratio of products to reactants once a reversible reaction has settled into equilibrium — a large Kc means the reaction favors products, a small one means it favors reactants.
The equilibrium constant Kc tells you the ratio of products to reactants once a reversible reaction has settled into equilibrium — a large Kc means the reaction favors products, a small one means it favors reactants. This calculator finds Kc for a simple A + B ⇌ C + D reaction from the equilibrium concentrations.
At equilibrium: [A] = 0.20 M, [B] = 0.15 M, [C] = 0.10 M, [D] = 0.10 M. Kc = (0.10×0.10) / (0.20×0.15) = 0.01/0.03 ≈ 0.333.
It's a value that describes the ratio of product concentrations to reactant concentrations (each raised to their stoichiometric coefficients) at chemical equilibrium.
K = [products]^coefficients ÷ [reactants]^coefficients, using equilibrium molar concentrations for each species in the reaction.
A large K (much greater than 1) means the reaction favors products at equilibrium; a small K (much less than 1) means it favors reactants.