Common Intermediate

Definition

A common intermediate is a species produced in one step of a reaction mechanism and consumed in another. It does not appear in the overall balanced equation for the reaction.

Analogy

Imagine you're baking cookies using several ingredients. Flour might be your common intermediate - it's used up when making dough but doesn't show up in your final product, just like an intermediate doesn't appear in the overall balanced equation for a chemical reaction.

Related terms

Reaction Mechanism: The step-by-step sequence of elementary reactions by which overall chemical change occurs.

Transition State Theory: This theory explains how intermediates form during a chemical reaction and transition into products.

Rate-Determining Step: The slowest step in a multi-step process that determines the overall rate at which the entire process proceeds.