Molar concentration

Molar concentration, or molarity, or simply concentration, is a term in chemistry, and its physical chemistry branch. It measures the moles of solute in a given volume of a solution or mixture.

In chemistry, the molar concentration,  is defined as the amount of a constituent  (usually measured in moles – hence the name) divided by the volume of the mixture : International Union of Pure and Applied Chemistry. Amount concentration, c. Compendium of chemical terminology, internet edition. 

The volume  in the definition  refers to the volume of the solution, not the volume of the solvent. One litre of a solution usually contains either slightly more or slightly less than 1 litre of solvent because when a substance dissolves in a solvent it causes volume of liquid to increase or decrease.

The reciprocal quantity represents the dilution (volume) which can appear in Ostwald's law of dilution.

 References 

 Other websites 
 Molarity -Citizendium

Category:Physical chemistry