= Solution
\b[<Volumetric analysis> determines an amount of substance from the measured volume of a reagent of known strength that reacts with it in a known proportion.] A measured <aliquot> is placed in a suitable vessel, the <standard solution> is delivered from a <burette>, and the volume required to reach the chosen <titration endpoint> is read. A <pipette> measures the <aliquot>; a <volumetric flask> prepares or dilutes the <standard solution>.
For a reaction $aA+bB\longrightarrow\text{products}$, if the <concentration> of the <titrant> $B$ is $c_B$ and the corrected volume delivered is $V_B$, then
$$
\boxed{n_A=\frac{a}{b}c_BV_B}.
$$
With volume in <litres> and concentration in <moles> per litre, the answer is an amount in <moles>. The corresponding <mass> is $m_A=M_A n_A$, using the appropriate <molar mass>. For an unknown solution of aliquot volume $V_A$,
$$
\boxed{c_A=\frac{a\,c_BV_B}{b\,V_A}}.
$$
These are modern symbols for the same proportional reasoning that a nineteenth-century analyst could express with equivalent weights and a specified standard solution.
<IUPAC Compendium of Chemical Terminology (Gold Book) by International Union of Pure and Applied Chemistry>[titration; volumetric titration, terms T06387 and 09055]{ref}
A suitable reaction is sufficiently rapid, complete and selective, with a recognisable endpoint. In an <acid-base titration>, an <indicator> can change colour near <neutralization>; other reactions use <precipitation>, <redox> or a colour intrinsic to a reagent. The observed <titration endpoint> must represent the required <equivalence point> closely enough. The reagent's nominal preparation alone is insufficient if its <concentration> changes in storage; <standardisation of a solution>, a <reagent blank> where needed, and correct reading of the <meniscus> control <systematic error>. A <titration> measures the intended <analyte> only insofar as interfering substances have been excluded or accounted for.
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