<P> Solubility may also strongly depend on the presence of other species dissolved in the solvent, for example, complex - forming anions (ligands) in liquids . Solubility will also depend on the excess or deficiency of a common ion in the solution, a phenomenon known as the common - ion effect . To a lesser extent, solubility will depend on the ionic strength of solutions . The last two effects can be quantified using the equation for solubility equilibrium . </P> <P> For a solid that dissolves in a redox reaction, solubility is expected to depend on the potential (within the range of potentials under which the solid remains the thermodynamically stable phase). For example, solubility of gold in high - temperature water is observed to be almost an order of magnitude higher (i.e. about ten times higher) when the redox potential is controlled using a highly oxidizing Fe O - Fe O redox buffer than with a moderately oxidizing Ni - NiO buffer . </P> <P> Solubility (metastable, at concentrations approaching saturation) also depends on the physical size of the crystal or droplet of solute (or, strictly speaking, on the specific surface area or molar surface area of the solute). For quantification, see the equation in the article on solubility equilibrium . For highly defective crystals, solubility may increase with the increasing degree of disorder . Both of these effects occur because of the dependence of solubility constant on the Gibbs energy of the crystal . The last two effects, although often difficult to measure, are of practical importance . For example, they provide the driving force for precipitate aging (the crystal size spontaneously increasing with time). </P> <P> The solubility of a given solute in a given solvent typically depends on temperature . Depending on the nature of the solute the solubility may increase or decrease with temperature . For most solids and liquids, their solubility increases with temperature . In liquid water at high temperatures, (e.g., that approaching the critical temperature), the solubility of ionic solutes tends to decrease due to the change of properties and structure of liquid water; the lower dielectric constant results in a less polar solvent . </P>

How compounds are ranked by levels of solubility