What role does a catalyst serve in a chemical reaction?

A catalyst plays a crucial role in a chemical reaction by speeding up the reaction without undergoing any permanent change itself. This means that after the reaction has occurred, the catalyst can be reused for additional reactions.

Catalysts lower the activation energy required for a reaction to proceed, allowing the reactants to convert into products more readily. By providing an alternative pathway for the reaction mechanism, catalysts facilitate the process, resulting in an increased rate of reaction.

Understanding this function is key, as it highlights how catalysts do not alter the equilibrium of a reaction or the final products formed; they simply enable the reaction to reach equilibrium faster. This is why option D accurately describes the role of a catalyst in chemical reactions.