Le Chatelier’s Principle

Chemistry ⇒ Chemical Kinetics and Equilibrium

Le Chatelier’s Principle starts at 11 and continues till grade 12. QuestionsToday has an evolving set of questions to continuously challenge students so that their knowledge grows in Le Chatelier’s Principle. How you perform is determined by your score and the time you take. When you play a quiz, your answers are evaluated in concept instead of actual words and definitions used.

See sample questions for grade 11

Describe the effect of decreasing the volume of a container on a gaseous equilibrium where the number of moles of gas is greater on the reactant side.

Describe the effect of increasing the concentration of a product in a reversible reaction at equilibrium.

Describe what happens to the equilibrium position if both reactant and product concentrations are increased equally.

Describe what happens to the equilibrium position when an inert gas is added to a reaction mixture at constant volume.

Explain how a catalyst affects the position of equilibrium according to Le Chatelier’s Principle.

Explain why changing the pressure only affects equilibria involving gases.

Explain why increasing the temperature of an endothermic reaction increases the yield of products.

Explain why the addition of an inert gas at constant pressure can affect the equilibrium position in a gaseous system.

For the reaction: 2A(g) \rightleftharpoons B(g) + C(g), if the total pressure is increased, what will happen to the equilibrium position?

For the reaction: 2NO(g) + O_2(g) \rightleftharpoons 2NO_2(g), what will happen if the temperature is increased, given that the reaction is exothermic?

For the reaction: 2NO_2(g) \rightleftharpoons N_2O_4(g), what will happen if the temperature is decreased, given that the reaction is exothermic?

For the reaction: 2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g), what will happen if more SO_2 is added?

For the reaction: CaCO_3(s) \rightleftharpoons CaO(s) + CO_2(g), what will happen if CO_2 is removed from the system?

For the reaction: H_2(g) + I_2(g) \rightleftharpoons 2HI(g), what will happen to the equilibrium if the volume of the container is doubled?

For the reaction: H_2O(l) \rightleftharpoons H_2O(g), what will happen to the equilibrium if the pressure is increased?

For the reaction: N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g), what will happen to the yield of NH_3 if the pressure is increased?

In an endothermic reaction at equilibrium, what is the effect of decreasing the temperature?

State Le Chatelier’s Principle.

A reaction at equilibrium is subjected to a sudden increase in pressure by decreasing the volume. The reaction is: PCl_5(g) \rightleftharpoons PCl_3(g) + Cl_2(g). Predict the effect on the equilibrium position and justify your answer.

A sealed container contains the equilibrium mixture: 2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g). Predict and explain the effect on the equilibrium position if the temperature is decreased, given that the forward reaction is exothermic.