Question

WHAT ARE described as the concentration ratio of a chemical amidst the two media at equilibrium.

Answer 1

$\huge\underline\mathrm\red{Partition\:coefficient}$

Partition coefficients are described as the concentration ratio of a chemical amidst the two media at equilibrium. The media can be gases such as air, liquids such as water or olive oil, or complex mixtures such as blood or other tissues....

$\huge\underline\mathrm\green{More\:to\:know}$

• A partition coefficient (P) or distribution coefficient (D) is the ratio of concentrations of a compound in a mixture of two immiscible solvents at equilibrium.

• This ratio is therefore a comparison of the solubilities of the solute in these two liquids. The partition coefficient generally refers to the concentration ratio of un-ionized species of compound, whereas the distribution coefficient refers to the concentration ratio of all species of the compound (ionized plus un-ionized).

• In the chemical and pharmaceutical sciences, both phases usually are solvents...Most commonly, one of the solvents is water, while the second is hydrophobic, such as 1-octanol..

• Hence the partition coefficient measures how hydrophilic ("water-loving") or hydrophobic ("water-fearing") a chemical substance is. Partition coefficients are useful in estimating the distribution of drugs within the body. Hydrophobic drugs with high octanol-water partition coefficients are mainly distributed to hydrophobic areas such as lipid bilayers of cells. Conversely, hydrophilic drugs (low octanol/water partition coefficients) are found primarily in aqueous regions such as blood serum.....