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 \(\left[\rm{B}\right]\). The common unit is mole per cubic decimetre (\(\pu{mol dm-3}\)) or mole per litre (\(\pu{mol L-1}\)) sometimes denoted by \(M\).