Molar Concentration

The molar concentration , or molarity , is the quantity of matter of aqueous solution per unit of volume of solution. Its symbol is C; however, most of the time, when one speaks successively about the concentration of several different chemical species, one uses rather the notation of the species (ex: = concentration in ion coppers II). Its usual unit is the mole by Liter (mol·L^-1) and its submultiples.

The concentration is a size Intensive like the Température or the Pression, i.e. which does not depend on the quantity of matter. It can be defined only if the medium is Homogène; its value being identical in each place of the solution.

A solution is known as of 1 molar if its molar concentration is of 1 mol·L^-1. It is principal the unit of concentration used in Chimie of the solution S.

It is possible to calculate the molar concentration formed by the solvent addition at the time of a Dilution, thanks to the formula:

Initial C_ {\ mathrm {}} \ cdot initial V_ {\ mathrm {}} = C_ {\ mathrm {final}} \ cdot final V_ {\ mathrm {}} still noted:

C_i \ cdot V_i = C_f \ cdot V_f \,

Indeed, the quantity of matter does not change during a dilution:

$n_ {initial} = n_ {final} \,$

And like $n = C \ cdot V$

Then: $C_ {\ mathrm {initial}} \ cdot initial V_ {\ mathrm {}} = C_ {\ mathrm {final}} \ cdot final V_ {\ mathrm {}}$

Either F the coefficient of dilution, one obtains: $F= \ frac {C_ {\ mathrm {initial}}} {C_ {\ mathrm {final}}} = \ frac {final V_ {\ mathrm {}}} {initial V_ {\ mathrm {}}}$

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