Answer
(a) $COCl_2$ being a product, the reaction shifts to the left.
(b) $Cl_{2}$ being a reactant, the reaction shifts to the right.
(c) $COCl_{2}$ being a product, the reaction shifts to the right.
Work Step by Step
(a) According to Le Chatelier's Principle, when a product is added to a reaction the equilibrium shifts to the left side (reactants) to lower the amount/concentration of product.
(b) According Le Chatelier's Principle, when a reactant is added to a reaction mixture the equilibrium shifts to the right side (product) to lower the amount/concentration of reactant.
(c) According to Le Chatelier's Principle, when a product is removed from a reaction mixture then the equilibrium shifts to right side (product) to increase the amount/concentrations of product.
