ALEKS Placement Chemistry Practice Exam 2026 - Free Chemistry Placement Practice Questions and Study Guide

A catalyst plays a crucial role in a chemical reaction by increasing the reaction rate. It achieves this by providing an alternative reaction pathway that has a lower activation energy compared to the uncatalyzed reaction. This lower energy threshold allows more reactant molecules to have sufficient energy to collide effectively and react, thus speeding up the overall reaction without being consumed in the process.

The formation of new products is a fundamental aspect of any reaction, whether catalyzed or not, and energy levels do change during reactions, but a catalyst specifically lowers the energy barrier for the reaction mechanism. Furthermore, while catalysts may have some stabilizing effects on certain reaction intermediates, their primary function is not to stabilize reactants but rather to enhance the speed at which products are formed.