Chemistry Regents Practice Test 2026 – Complete Prep Resource

A catalyst increases the rate of a chemical reaction by providing an alternative reaction pathway with a lower activation energy, allowing the reaction to proceed more quickly. Importantly, a catalyst is not consumed in the reaction; it can participate in the reaction mechanism and facilitate the process, but it is regenerated at the end of the reaction. This characteristic means that a small amount of catalyst can be used repeatedly, which is a significant advantage in many chemical processes.

The other roles suggested, such as decreasing the energy needed or altering the temperature of the reaction, do not accurately define the primary function of a catalyst. While it's true that a catalyst lowers the activation energy, it does not reduce the overall energy of the reactants or products. Additionally, catalysts do not inherently change the temperature; instead, they work under the existing temperature conditions of the reaction.