Written by the Fiveable Content Team โข Last updated September 2025
Written by the Fiveable Content Team โข Last updated September 2025
Definition
Reactants are the starting substances in a chemical reaction that undergo change to form products. They are present on the left side of a chemical equation.
5 Must Know Facts For Your Next Test
Reactants participate directly in the chemical reaction and get consumed during the process.
In a balanced chemical equation, the number of atoms for each element in the reactants must equal the number of atoms for those elements in the products.
The physical state of reactants (solid, liquid, gas, or aqueous) is often indicated in parentheses next to their chemical formulas.
Stoichiometric coefficients represent the relative amounts of reactants needed for the reaction to proceed completely.
Limiting reactant is the reactant that gets completely consumed first, thereby limiting the amount of product formed.