What is "mother liquor"

Mother \Moth"er\, a. Received by birth or from ancestors; native, natural; as, mother language; also acting the part, or having the place of a mother; producing others; originating. It is the mother falsehood from which all idolatry is derived. --T. Arnold. Mother cell (Biol.), a cell which, by endogenous divisions, gives rise to other cells (daughter cells); a parent cell. Mother church, the original church; a church from which other churches have sprung; as, the mother church of a diocese. Mother country, the country of one's parents or ancestors; the country from which the people of a colony derive their origin. Mother liquor (Chem.), the impure or complex residual solution which remains after the salts readily or regularly crystallizing have been removed. Mother queen, the mother of a reigning sovereign; a queen mother. Mother tongue.

1. A language from which another language has had its origin.

2. The language of one's native land; native tongue.

   Mother water. See Mother liquor (above).

   Mother wit, natural or native wit or intelligence.

n. (context chemistry English) The solution remaining after a product has been removed by crystallization etc.

A mother liquor is the part of a solution that is left over after crystallization. It is encountered in chemical processes including sugar refining.

In crystallization, a solid (usually impure) is dissolved in a solvent at high temperature, taking advantage of the fact that most solids are more soluble at higher temperatures. As the solution cools, the solubility of the solute in the solvent will gradually become smaller. The resultant solution is described as supersaturated, meaning that there is more solute dissolved in the solution than would be predicted by its solubility at that temperature. Crystallization can then be induced from this supersaturated solution and the resultant pure crystals removed by such methods as vacuum filtration and centrifugal separators. The remaining solution, once the crystals have been filtered out, is known as the mother liquor, and will contain a portion of the original solute (as predicted by its solubility at that temperature) as well as any impurities that were not filtered out. Second and third crops of crystals can then be harvested from the mother liquor.