Explain why catalysts do not change the position of equilibrium.

Catalysts speed up both the forward and reverse reactions equally, allowing the system to reach equilibrium faster without altering the concentrations of reactants and products at equilibrium. This answer is anchored to Equilibrium and Le Chatelier's principle.

Catalysts speed up both the forward and reverse reactions equally, allowing the system to reach equilibrium faster without altering the concentrations of reactants and products at equilibrium. is the best answer because it directly supports the AQA A-Level Chemistry objective to define dynamic equilibrium in a closed system. This reasoning is anchored to Equilibrium and Le Chatelier's principle in Chemical equilibria, Le Chatelier's principle and Kc, and it separates dynamic equilibrium from similar A-Level ideas rather than relying on a vague recall statement. Other options are weaker if they use the wrong evidence, calculation, mechanism, observation, unit, or conclusion for this subtopic.