15325 IUPAC Gold Book - dystonic reaction 10.1351/goldbook.15325 15325 current 1 Reversible dissolution in an isothermal, isobaric system of three or more components characterized by dissolution and saturation with a stoichiometric compound consisting of two or more of these components. The equilibrium process is, for example, \[\ce{AB.p H2O A(aq, sat) + B(aq, sat) + p H2O(l)}\] The chemical potential of solvent and consequently its partial pressure reaches a maximum value at the dystonic composition or point, which is isothermally and isobarically invariant. Dystonic points have been detected in aqueous media only. From Greek δύστονος, difficult (highest) tension (vapor pressure). Systems \(\ce{Na2SO4 + ZnSO4 + H2O}\), \(\ce{Na2SO4 + CdSO4 + H2O}\), \(\ce{Na2SO4 + CuSO4 + H2O}\). components https://goldbook.iupac.org/terms/view/16268 eutonic reaction https://goldbook.iupac.org/terms/view/15327 peritonic reaction https://goldbook.iupac.org/terms/view/15344 PAC, 2008, 80, 233. 'Glossary of terms related to solubility (IUPAC Recommendations 2008)' on page 244 (https://doi.org/10.1351/pac200880020233) https://goldbook.iupac.org/terms/view/15325/html https://goldbook.iupac.org/terms/view/15325/json https://goldbook.iupac.org/terms/view/15325/plain Citation: 'dystonic reaction' 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.15325 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. 2026-05-09T20:41:17+00:00