Assessment and Qualifications Alliance (AQA) GCSE Chemistry Paper 2 Practice Exam

Catalysts enhance the reaction rate by providing an alternative pathway for the reaction that has a lower activation energy. Activation energy is the minimum amount of energy required for a reaction to occur. By lowering this energy threshold, catalysts allow more reactant molecules to have sufficient energy to successfully collide and react, thereby increasing the frequency of effective collisions that lead to product formation.

This mechanism does not involve changing the temperature or the concentration of the reactants, nor does it decrease the surface area; rather, it focuses on modifying the energy dynamics of the reaction process. The presence of a catalyst enables reactions to proceed faster without being consumed in the process, which is a key aspect of how catalysts function in both industrial and biological contexts.