# What is concentration 2

Under the Molarity (obsolete term) or Amount of substance concentration (Formula symbol: c) one understands the quotient from the amount of substance (n) of a solute X and the volume (V.) of the solution. It can be specified in the unit mole per liter: If the molar mass is known, the mass concentration can be calculated from the molar concentration, and the particle number concentration can be determined from the molar concentration with the help of Avogadro's constant.

The symbol "M."used for the unit of measurement mol / L and also used together with SI prefixes; however, this notation is not compatible with the International System of Units (SI).

The molarity (molar concentrations) must not match the Molality be confused!

In Anglo-Saxon literature, "concentration" always means the substance concentration.

A 2.5 molar (outdated representation also: 2.5 M) aqueous sulfuric acid is meant that contains 2.5 mol of sulfuric acid molecules in 1 liter of solution at a certain temperature; this is based on the usual unit mol / l;

### Sample calculations

In a 0.8 molar (0.8 M) sulfuric acid solution (molar mass of sulfuric acid: 98.08 g / mol) there are 0.8 mol of H per liter of solution2SO4 contain. The corresponding mass at H2SO4 for a volume V. = 3 liters of such sulfuric acid is: The number of particlesN a 3 millimolar (3 mM) solution of cane sugar in water for one volume of solution V. = 2 cubic centimeters, where NA. (Avogadro's constant) indicates the number of particles per mole is: 