Le Chatelier Principle and its Application MCQs

41. In an exothermic reaction, what will happen if the temperature is decreased?

• A) Equilibrium will shift towards the products
• B) Equilibrium will shift towards the reactants
• C) No change in equilibrium
• D) The reaction will stop
• Answer: A

42. Which of the following changes would shift the equilibrium of a reaction to favor the products?

• A) Adding more products
• B) Adding more reactants
• C) Removing reactants
• D) Increasing temperature for an exothermic reaction
• Answer: B

43. For a reversible reaction at equilibrium, what happens when a product is removed?

• A) The reaction will stop
• B) Equilibrium will shift to produce more products
• C) The rate of the forward reaction will decrease
• D) The reverse reaction will dominate
• Answer: B

44. Le Chatelier’s principle can be used to explain why increasing pressure in a reaction involving gases:

• A) Shifts equilibrium towards the side with more gas molecules
• B) Shifts equilibrium towards the side with fewer gas molecules
• C) Has no effect on equilibrium
• D) Increases the rate of the reverse reaction
• Answer: B

45. In an exothermic reaction, decreasing the temperature will:

• A) Shift equilibrium towards the reactants
• B) Shift equilibrium towards the products
• C) Have no effect on equilibrium
• D) Stop the reaction entirely
• Answer: B

46. According to Le Chatelier’s principle, adding heat to an endothermic reaction will:

• A) Shift equilibrium to the right
• B) Shift equilibrium to the left
• C) Increase the concentration of products
• D) Have no effect
• Answer: A

47. In a chemical equilibrium, if pressure is decreased, the system will shift to:

• A) The side with fewer moles of gas
• B) The side with more moles of gas
• C) The side with an equal number of moles
• D) The reactants
• Answer: B

48. What happens if a catalyst is added to a system at equilibrium?

• A) Equilibrium shifts to the right
• B) Equilibrium shifts to the left
• C) Both the forward and reverse reactions are sped up
• D) Only the forward reaction is sped up
• Answer: C

49. Which of the following factors does not affect the position of equilibrium?

• A) Pressure
• B) Temperature
• C) Concentration
• D) Catalyst
• Answer: D

50. If the pressure on the following equilibrium system is increased, 2NO₂ ⇌ N₂O₄, the position of equilibrium will:

• A) Shift to the right
• B) Shift to the left
• C) Not change
• D) Stop the reaction
• Answer: A