First, we can qualitatively describe the content of the reaction mixture by looking at the magnitude of Kc.Second, we can determine the direction in which a reaction will proceed by comparing Kc to the value of the reaction quotient, Q, which has the same expression as Kc but uses nonequilibrium values.Finally, we can determine equilibrium concentrations given the initial concentrations and the value of Kc.When Kc is very large (>102), the equilibrium mixture is mostly products. When Kc is very small ( 0.01, at equilibrium there will be substantial amounts of both reactants and products.Reaction Quotient, Q The reaction quotient has the same form as the equilibrium constant, but uses initial concentrations for its value.When Kc > Q, the reaction proceeds to the right.When Kc < Q, the reaction proceeds to the left.When Kc = Q, the reaction is at equilibrium.