Organic Chemistry MCAT Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

A catalyst plays a crucial role in chemical reactions by providing an alternative pathway with lower activation energy. This means that the presence of a catalyst allows reactants to convert to products more easily and quickly than they would without it. By lowering the activation energy barrier, the catalyst increases the rate at which the reaction occurs, making it more efficient.

Importantly, a catalyst does not alter the equilibrium position of a reaction, which means it does not affect the overall yield of products versus reactants at equilibrium. It simply accelerates the rate at which equilibrium is reached. Additionally, a catalyst is not consumed in the reaction; it remains unchanged after the reaction is complete and can be used repeatedly. This characteristic distinguishes a catalyst from reactants that are converted into products.

In summary, the correct answer highlights that the primary function of a catalyst in a reaction is to facilitate the process by providing a more favorable pathway for the reaction to occur.