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Dissociation in chemistry is a general process in which molecules (or ionic compounds such as salts, or complexes) separate or split into other things such as atoms, ions, or radicals, usually in a reversible manner.
A solubility equilibrium exists when a chemical compound in the solid state is in chemical equilibrium with a solution containing the compound. This type of equilibrium is an example of dynamic equilibrium in that some individual molecules migrate between the solid and solution phases such that the rates of dissolution and precipitation are equal to one another.
For example, if you add sodium chloride to water, the salt will dissociate into the ions sodium(+aq) and chloride(-aq). The equilibrium constant for this dissociation can be predicted by the change in Gibbs energy of this reaction. The Born equation is used to estimate Gibbs free energy of solvation of a gaseous ion.
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
If a substance is present as several chemical species in the partition system due to association or dissociation, each species is assigned its own K ow value. A related value, D, does not distinguish between different species, only indicating the concentration ratio of the substance between the two phases.
Typically, this will be to extract organic compounds out of an aqueous phase and into an organic phase, but may also include extracting water-soluble impurities from an organic phase into an aqueous phase. [1] [2] Common extractants may be arranged in increasing order of polarity according to the Hildebrand solubility parameter:
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Oxalate (systematic IUPAC name: ethanedioate) is an anion with the chemical formula C 2 O 2− 4. This dianion is colorless. It occurs naturally, including in some foods. It forms a variety of salts, for example sodium oxalate (Na 2 C 2 O 4), and several esters such as dimethyl oxalate ((CH 3) 2 C 2 O 4). It is a conjugate base of oxalic acid.