# Chemical concentration ratios and their conversion

1 Molar concentration
The molar concentration of a substance B in a solution of the quotient of the number of moles of substance B and the volume of the solution Lg The corresponding SI unit is 1 mol / m³. Furthermore, mol/l,  mol/dm ³, mmol/l, mol/ml, kmol/m³ permitted. A solution with the molar concentration of 1 mol/l is also referred to as a 1 molar (abbreviated 1 M).

B = n B / v Lg

2 Equivalent concentration
The equivalent concentration, also called norm, of a substance B in a solution is defined as the quotient of the Soffmenge the equivalent (the number of equivalents is given by the stoichiometric value z of a molecule) and the volume of the solution. Apply the same units as the molar concentration.
A solution of the equivalent concentration c Ä, B of 1 mol / l is referred to as 1 Normal (short 1N).

Ä, B = n Ä, B / v Lg = c B * z = (n B * z) / v Lg

3 Molality
The molality of a substance B in a solution is defined as the quotient of the number of moles of substance B and the mass of the solvent Lm The resulting valid SI unit is 1 mol/kg.
A solution of molality m c, B = 1 mol / kg is also designated as 1 molal.

m, B = n B / m Lm

4 Mass concentration
The mass concentration of a substance B in a solution is defined as the ratio of the mass of the substance B and the volume of the solution.
The SI unit is 1 kg / m³. Furthermore, the following units are permitted: g / l, mg / ml, mg / l, g / cm ³, ug / ml. Are not permitted ratio units such as%, ‰, ppb and ppm and mg% and g% (= g/100 ml)

ρ B = m B / v Lg

5 Volume concentration
The volume concentration of a substance B in a mixing stage is defined as the quotient of the volume of the substance B, and the total volume of the mixing phase.
The corresponding SI unit is m³ / m³. Furthermore permitted are l / l, l / m³, cm ³ / l and l / hl.

σ B = v B / v tot

6 Amount of substance
The amount of substance (mole fraction called) of a substance B in a mixed phase is defined as the quotient of the molar amount of the substance B and the sum of the molar amounts of all components of the mixed phase.
The SI unit is mol / mol, and mmol / mol, mol / kmol,% ‰, ppm and ppb are permitted.

χ B = n B / n Σ i

7 Mass fraction
The mass fraction (also called mass fraction) of a substance B in a mixed phase is defined as the ratio of the mass of the substance B and the sum of the masses of all the components of the mixed phase.
The associated SI unit is kg / kg, g / kg, mg / g, mg / kg, g / g% ‰, ppm and ppb are also permitted.

B = m B / m Σ i

8 Volume fraction
The volume fraction (also called the volume fraction) of a substance B in a mixing stage is defined as the quotient of the volume of the substance B and the sum of the volumes of all components of the mixed phase.
The SI unit is m³ / m³. Furthermore, are permitted: l / l, l / m³, cm ³ / l, ml / l,%, ‰, ppm and ppb.

φ B = v B / v Σ i

## Conversion of concentration variables

cBcm, BρBχBwB
cB = cB( cm, B * ρ) / (1+ cm, B * MB)ρB/MB(xB * ρ) / (Σ χi * Mi)(wB * ρ)/MB
cn, B =cB/ (ρ - cB*MB)cm, BρB/ (MB(ρ - ρB))χB/ (χLm * MLm)wB/ (wLm * MB)
ρB =cB * MB(cm, B * MB * ρ) / (1 + cm, B * MB)ρBB * MB * ρ) / Σ χi * Mi)wB * ρ
χB =(cB * MLm) / (ρ + cB(MLm - MB))(cm, B * MLm) / (1 + cm, B * MLm))B * MLm) / (ρB * MLm + MB * (ρ - ρB))χBwB / ( MB * Σ (wi / Mi))
wB =(cB * MB) / ρ(cm, B * MB) / ( 1 + cm, B* MB)ρB / ρB * MB) / (Σ χi * Mi)wB