Amount of a constituent divided by the volume of the mixture. Also called amount-of-substance concentration, substance concentration (in clinical chemistry) and in older literature molarity. For entities B it is often denoted by B. The common unit is mole per cubic decimetre (mol dm-3) or mole per litre (mol L-1) sometimes denoted by M.
See also: concentration
Green Book, 2nd ed., p. 42 (https://dev.goldbook.iupac.org/files/pdf/green_book_2ed.pdf)