06023 IUPAC Gold Book - stoichiometric concentration 10.1351/goldbook.S06023 S06023 current 1 The stoichiometric concentration, \(c_{\rm{B}}\), of a component B in a system is given by the expression: \[c_{\rm{B}}=\frac{n_{\rm{B}}}{V}\] where \(n_{\rm{B}}\) is the stoichiometric amount of substance of component B in the system and \(V\) is the volume of the system. The component added to the system may dissociate or react with other components to form a series of derived components and only a fraction of the original component may actually exist in a free form in the system. It is therefore essential to distinguish between the stoichiometric concentration and the amount-of-substance concentration of the free form of the component in the system. Sometimes stoichiometric quantities are indicated by a subscript (\(_{\circ}\)), e.g. \(n_{\rm{o,B}}\), \(c_{\rm{o,B}}\). In clinical chemistry, the term stoichiometric concentration is rarely employed. Instead, the name of the component is modified to indicate inclusion of the various derived forms, e.g. mixtures of a defined chemical component and its derivatives may be denoted by the plural form of the name of the pure unchanged substance, or to indicate the sum of components specified in individual quantities the specification 'total' may be employed. amount of substance https://goldbook.iupac.org/terms/view/A00297 amount-of-substance concentration https://goldbook.iupac.org/terms/view/A00298 stoichiometric https://goldbook.iupac.org/terms/view/S06021 PAC, 1984, 56, 567. 'Physicochemical quantities and units in clinical chemistry with special emphasis on activities and activity coefficients (Recommendations 1983)' on page 568 (https://doi.org/10.1351/pac198456050567) https://goldbook.iupac.org/terms/view/S06023/html https://goldbook.iupac.org/terms/view/S06023/json https://goldbook.iupac.org/terms/view/S06023/plain Citation: 'stoichiometric concentration' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.S06023 The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using. 2026-07-01T11:15:01+00:00