Question

When the concentration of PCl₃(g) is increased to 1.2 M, the ratio of products to reactants is 4.0. The equilibrium constant for the reaction is 24. In which direction will the reaction shift to regain equilibrium?
A. toward the reactants
B. toward the products

Answer 1

Answer:

B. toward the products

Explanation:

The equilibrium constant of an equilibrium reaction measures relative amounts of the products and the reactants present at equilibrium. It is the ratio of the concentration of the products and the reactants each raised to their stoichiometric coefficients. The concentration of the liquid and the gaseous species does not change and thus is not written in the expression.

Thus, on increasing the concentration of any one of the reactant, the value of equilibrium constant will decrease.

The reaction quotient of an equilibrium reaction measures relative amounts of the products and the reactants present during the course of the reaction at  particular point in the time.

Q < Kc , reaction will proceed in forward direction.

Q > Kc , reaction will proceed in backward direction.

Q = Kc , reaction at equilibrium.

Since, given that The equilibrium constant for the reaction is 24. On increasing the concentration of one of the reactant, the reaction quotient will become less than Kc and thus, go in forward direction which means that towards the product.