Carbon monoxide and chlorine combine in an equilibrium reaction to produce the highly toxic product, phosgene (COCl₂) CO(g) + Cl₂(g) ⇄ COCl₂(g)
If the equilibrium constant for this reaction is K_c = 248, predict, if possible, what will happen when the reactants and product are combined with the concentrations shown.
[CO] = [Cl₂] = 0.010 M; [COCl₂] = 0.070 M

Question

Quizplus · Accepted Answer

To determine the direction of the reaction, we can use the reaction quotient (Qc) and compare it to the equilibrium constant (Kc). If Qc is greater than Kc, the reaction will proceed to the left to reach equilibrium. If Qc is less than Kc, the reaction will proceed to the right to reach equilibrium. If Qc is equal to Kc, the reaction is at equilibrium and no change in concentrations will occur.

Qc = [COCl]/([CO][Cl]) = 0.070/(0.010)(0.010) = 700
Kc = 248

Since Qc is greater than Kc, the reaction will proceed to the left to reach equilibrium. This means that the concentration of COCl will decrease, and the concentrations of CO and Cl2 will increase until the Qc value equals Kc.

Carbon Monoxide and Chlorine Combine in an Equilibrium Reaction to Produce