In the context of chemical reactions, what is a limiting reactant?

In a chemical reaction, a limiting reactant is defined as the reactant that is completely consumed first, limiting the amount of product that can be formed. When one reactant is used up, the reaction cannot continue, even if other reactants are still available in excess. This makes the limiting reactant crucial for determining the theoretical yield of the products, as it directly controls the rate at which the reaction proceeds.

Choosing the correct reactant as limiting ensures accurate calculations regarding how much product can be produced from the given amounts of reactants. This concept is fundamental to stoichiometry in chemistry, allowing chemists to predict and measure the outcomes of chemical reactions efficiently. Understanding this helps in various applications, such as optimizing reactant usage in industrial processes or laboratory experiments.