Question

Calculate the reaction quotient, Qc, for the reaction: 2 NO2 (g) + Cl2 (g) ⇌ 2 NO2Cl (g)At a certain temperature, the concentrations were found to be: [NO2] = 0.15 M, [Cl2] = 0.20 M, and [NO2Cl] = 0.10 M.Is the reaction at equilibrium? If not, which direction would the reaction proceed to reach equilibrium?

Answer 1

To determine if the reaction is at equilibrium, we need to calculate the reaction quotient, Qc, and compare it to the equilibrium constant, Kc, at that temperature. The reaction quotient is calculated using the concentrations of the reactants and products:Qc = [NO2Cl]^2 /  [NO2]^2 * [Cl2] Using the given concentrations:Qc =  0.10 M ^2 /   0.15 M ^2 *  0.20 M  Qc = 0.01 /  0.0225 * 0.20 Qc = 0.01 / 0.0045Qc  2.22Now, we need to compare Qc to Kc at that temperature. If Qc = Kc, the reaction is at equilibrium. If Qc < Kc, the reaction will proceed to the right  toward the products  to reach equilibrium. If Qc > Kc, the reaction will proceed to the left  toward the reactants  to reach equilibrium.Unfortunately, we do not have the value of Kc at this temperature. However, we can determine the direction the reaction will proceed based on the value of Qc:- If Kc is greater than 2.22, the reaction will proceed to the right  toward the products  to reach equilibrium.- If Kc is less than 2.22, the reaction will proceed to the left  toward the reactants  to reach equilibrium.- If Kc is equal to 2.22, the reaction is already at equilibrium.