<P> In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture . Several types of mathematical description can be distinguished: mass concentration, molar concentration, number concentration, and volume concentration . The term concentration can be applied to any kind of chemical mixture, but most frequently it refers to solutes and solvents in solutions . The molar (amount) concentration has variants such as normal concentration and osmotic concentration . </P> <P> Often in informal, non-technical language, concentration is described in a qualitative way, through the use of adjectives such as "dilute" for solutions of relatively low concentration and "concentrated" for solutions of relatively high concentration . To concentrate a solution, one must add more solute (for example, alcohol), or reduce the amount of solvent (for example, water). By contrast, to dilute a solution, one must add more solvent, or reduce the amount of solute . Unless two substances are fully miscible there exists a concentration at which no further solute will dissolve in a solution . At this point, the solution is said to be saturated . If additional solute is added to a saturated solution, it will not dissolve, except in certain circumstances, when supersaturation may occur . Instead, phase separation will occur, leading to coexisting phases, either completely separated or mixed as a suspension . The point of saturation depends on many variables such as ambient temperature and the precise chemical nature of the solvent and solute . </P>

What is the meaning of concentration in science