What is the significance of a catalyst in a chemical reaction?

The significance of a catalyst in a chemical reaction primarily lies in its ability to lower the activation energy required for the reaction to proceed. Activation energy is the minimum energy barrier that reactants must overcome for a reaction to occur. By lowering this barrier, a catalyst enables more molecules to have sufficient energy to react at a given temperature, thus increasing the rate at which the reaction occurs without being consumed in the process.

This property of catalysts allows them to speed up reactions without altering the overall thermodynamics or equilibrium of the system. Consequently, while a catalyst decreases the time it takes for a reaction to reach equilibrium, it does not change the position of the equilibrium itself or affect the yields of products at equilibrium. Thus, the key role of a catalyst is enhancement of reaction rate through a reduction in activation energy, which is precisely captured in the correct response.