In chemical reaction mechanisms, what is the role of intermediates?

Intermediates play a critical role in chemical reaction mechanisms as transient species formed during the transformation of reactants into products. These compounds are created at some point during the reaction pathway and exist for a short time before being converted into the final products. The formation of intermediates helps to illustrate the stepwise process of a reaction, providing insight into the mechanism at work. They are central to understanding how reactants interact and evolve into products, often showcasing the complex nature of chemical transformations.

In contrast, other options present different aspects that do not accurately describe intermediates. Final products refer to the end result of a reaction rather than species that appear during the process. Catalysts, while they may speed up reactions, do not change during the reaction and are not the same as intermediates. Byproducts are substances produced in a reaction but are not involved in the transformation of reactants to products, and they may not be transient. Hence, the role of intermediates is best captured by describing them as transient species formed during reactant transformation.