The equivalence point, or stoichiometric point, of a chemical reaction is the point at which an added titrant is stoichiometrically equal to the number of moles of substance (known as analyte) present in the sample: the smallest amount of titrant that is sufficient to fully neutralize or react with the analyte. In some cases there are multiple equivalence points which are multiples of the first equivalent point, such as in the titration of a diprotic acid.
A graph of the titration curve exhibits an inflection point at the equivalence point—where the graph is steepest. A striking fact about equivalence is that in a reaction the equivalence of the reactants as well as products is conserved.
The endpoint (related to, but not the same as the equivalence point) refers to the point at which the indicator changes color in a colorimetric titration.
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