Vocabulary: Concentration massique (Cm) represents mass per unit volume, while concentration molaire (C) represents moles per unit volume.

Definition: Density $d$ is defined as the ratio of the density of a substance to a reference density, typically water, and is dimensionless.

Example: The relationship between mass and molar concentration is expressed as Cm = C × M, where Cm is in g/L, C in mol/L, and M in g/mol.

Highlight: The molar volume of a gas (V) can be calculated using the relationship V(gas) = n × Vm, where Vm is the molar volume in L/mol.

Definition: Mass density (ρ) is defined as the mass of a substance per unit volume, typically expressed in g/cm³.

Example: The quantity of matter can be determined from concentration and volume using n = C × V, where n is in moles, C in mol/L, and V in L.

Definition: Avogadro's number (NA) is defined as 6.02 × 10²³ molecules per mole, serving as a fundamental constant in chemical calculations.

Example: The calculation of molar mass for CH₄N₂O demonstrates how to sum the atomic masses of individual elements: M(CH₄N₂O) = M(C) + 4×M(H) + 2×M(N) + M(O).

Highlight: The relationship between mass and molar quantity is expressed through the equation m(species) = n × M(species), where m is in grams, n in moles, and M in g/mol.