substance or compound that is added to a system in order to bring about a chemical reaction, or added to see if a reaction occurs
(Redirected from Reactants)

A reagent is a chemical used to test for other chemicals. For example, potassium dichromate is used to test for alcohol, and nitric acid can be used to test for gold. Normally there is an obvious change, such as a color change or the formation of a solid substance.