https://doi.org/10.1351/goldbook.15325
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, \[\ce{AB.p H2O <=> A(aq, sat) + B(aq, sat) + p H2O(l)}\]
Notes:
- 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).
Examples: Systems \(\ce{Na2SO4 + ZnSO4 + H2O}\), \(\ce{Na2SO4 + CdSO4 + H2O}\), \(\ce{Na2SO4 + CuSO4 + H2O}\).
See also: eutonic reaction, peritonic reaction