reaktants

Reaktants are the substances that participate in a chemical reaction and are consumed to form products. In a chemical equation, reaktants appear on the left-hand side and are transformed into products on the right-hand side. They can be elements, compounds, or mixtures that undergo chemical change during the reaction. In English-language texts, the term reactants is standard, while reaktants is used in cross-language contexts.

The quantities of reaktants are described by stoichiometric coefficients, which express the molar ratios needed for the reaction under given conditions. The concept of a limiting reaktant explains why reactions stop when one substance is used up, even if others remain in excess. Catalysts and reagents used to initiate a reaction may not be consumed; catalysts are not counted among the reaktants for stoichiometric balance.

Examples illustrate the concept. In combustion, CH4 + 2 O2 -> CO2 + 2 H2O, the reaktants are CH4 and O2. In neutralization, HCl + NaOH -> NaCl + H2O, the reaktants are HCl and NaOH. In multi-step syntheses, initial reaktants may be converted to intermediates before final products are formed; intermediates are not considered reaktants in the overall equation once formed.