Chapter 15, Problem 11SAQ

What is the effect of adding helium gas (at constant volume) to an equilibrium mixture of this reaction:

   $\text{CO}\left(g\right)+\text{Cl}\left(g\right)\rightleftharpoons {\text{COCl}}_{\text{2}}\left(\text{g}\right)$

• The reaction does not shift either direction.
• The reaction shifts toward the products.
• The reaction shifts toward the reactants.
• The reaction slows down.