VII. Quantitative aspect of matter … (copy)

VII. Quantitative aspect of matter👌 

VII.1. The mole numbers. 🙂

The mole number is the ratio between the mass of the compound and its molar mass. 👌

Or: n: mole number, m: the mass of the compound, M: the molar mass of the compound. 

VII.2. Molar concentration or molarity

 The molarity of a solution is the ratio of the number of moles of solute in a volume (expressed in litres) of solution, the unit of which is the mole per litre [mol/l]. It is represented by the symbol M. 

VII.3. Molality The molality of a solution, 

the unit of which is represented by the symbol m, is the number of moles of solute per kilogram of solvent. The molality (m) cannot be calculated from the molarity (M) Or normality (N) unless the density of the solution is known. This concentration has the advantage of not depending on the volume of the solution and therefore on the temperature and pressure.