Mole Concepts

Mole Concepts

2.2

Mole Concept

Mole

SI unit of amount of substance.
Symbol: mol
1 mol of a substance = \(6.02214076 \times 10 ^{23}\) elementary entities of the substance.
Avogadro constant, \(N_A\) or Avogadro number = \(6.02 \times 10 ^{23} \text{ mol}^{-1}\)
1 mol of a substance consists of \(6.02 \times 10 ^{23} \) particles.

Number of mole and number of particles

Conversion Factor between Number of Moles and Number of Particles

\(\,\\ \text{Number of mole, }n = \dfrac{\text{Number of particles}}{N_A} \)

Number of mole and mass of a substance

Definition of molar mass

The mass of a substance that contains one mole of the substance

Conversion of the Number of Moles to the Mass of Substance

\(\, \\ \text{Number of mole, }n = \dfrac{\text{Mass (g)}}{\text{Molar mass (g mol}^{-1})} \\ \)

Number of moles of a gas and its volume

At the same temperature and pressure, equal volumes of all gases contain the same number of particles.
One mole of any gas at room temperature(25℃) and pressure of 1 atm occupies a volume of \(\text{24 dm}^3\) (or \(\text{24 000 cm}^3\)).
At standard temperature and pressure, s.t.p. ( 0℃ and 1 atm) 1 mole of gas occupies \(\text{22.4 dm}^3\) of volume.

Conversion of the number of moles of a gas to its volume

\(\, \\ \text{Number of mole, }n = \dfrac{\text{Volume}}{\text{Molar volume}} \\ \)