distribution coefficient

chemistry

Also known as: distribution ratio

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

June 25, 2026

Quick Summary

The term "distribution coefficient" in chemistry refers to the ratio of the concentrations of a substance dissolved in two immiscible liquids at equilibrium. This ratio is characteristic of the compound and the specific pair of solvents used. Substances with different molecular structures typically have widely varying distribution coefficients, allowing for their separation. However, very similar substances, like proteins, have similar coefficients, requiring numerous transfers for complete separation. This principle is fundamental to separation methods like countercurrent distribution, which is used in chemical analysis and purification.1

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

3 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

separation and purification
Separations based on equilibria
…described in terms of the distribution coefficient, K, by the equationin which the concentrations in the equilibrium state are considered. For K = 1, there are equal concentrations of the dye in the two phases; for K > 1, more dye would be found in the benzene phase at equilibrium.…
Read More
…described in terms of the distribution coefficient, K, by the equationin which the concentrations in the equilibrium state are considered. For K = 1, there are equal concentrations of the dye in the two phases; for K > 1, more dye would be found in the benzene phase at equilibrium.…
Read More

countercurrent distribution
…the two solvents, called the distribution coefficient, is characteristic of the compound and of the solvent pair. Compounds that have dissimilar molecular structures usually have widely different distribution coefficients, and mixtures of such compounds can be separated satisfactorily by one or a few transfers between a suitable solvent pair in…
Read More
…the two solvents, called the distribution coefficient, is characteristic of the compound and of the solvent pair. Compounds that have dissimilar molecular structures usually have widely different distribution coefficients, and mixtures of such compounds can be separated satisfactorily by one or a few transfers between a suitable solvent pair in…
Read More

liquid
Solutions and solubilities
…in water is called the distribution coefficient, and it is clear that for an efficient extraction process it is desirable to have as large a distribution coefficient as possible.
Read More
…in water is called the distribution coefficient, and it is clear that for an efficient extraction process it is desirable to have as large a distribution coefficient as possible.
Read More