Molalities

Part of speech: noun

Definitions

1. A measure of concentration that refers to the number of moles of solute per kilogram of solvent in a solution
2. The term used to quantify how much solute is dissolved in a specific amount of solvent
3. An expression defining the ratio of solute in moles to solvent in kilograms for solutions in chemistry

Etymology: "Molalities" is the plural of "molality", a chemistry term for the amount of solute dissolved per kilogram of solvent. The noun is built from "molal", the adjective formed from "mole" (the unit of amount of substance) and the suffix "-al", with "-ity" added on top to turn the quality into a measurable noun. Chemists therefore have two layers of coinage in the term: the unit name, and the quantity name derived from it. The ending "-ity" has a long pedigree. It passed from Latin "-itas" through Old French "-ite" into Middle English "-ite", and eventually settled into the modern English "-ity" that appears in words such as "density" and "purity". Attaching it to "molal" simply follows the same pattern that produced those older nouns, so the chemist's coinage sounds as though it has always existed.

Synonyms: concentrations, dilutions, solutions, compositions, mixtures