In tribute to Avogadro, also the number of particles (atoms, molecules, ions or other particles) in 1 mole of a substance:
It was named after Avogadro as the Avogadro constant or Avogadro number. The Avogadro constant is one of the seven SI base units and represented by NA.
The Avogadro’s Law can be used for comparing the same substance under two different sets of conditions:
V1 / n1 = V2 / n2
Molar Volume of Gases
One of the most practical results of this law is the molar volume of a gases, Vm, which is about:
Vm = 22.4 dm3 / mol
It means, at standard temperature (273.15 K, 0°C) and standard atmospheric pressure (101.325 kPa) the molar volume is the same for all ideal gases. Note that, it is under the ideal gas assumption. This value is strongly dependent on the pressure and the temperature. For example:
- for 273.15 K (0°C) and 100.00 kPa, the molar volume of an ideal gas is 22.71 dm3.mol−1.
- for 298.15 K (25°C) and 100.00 kPa, the molar volume of an ideal gas is 24.79 dm3.mol−1.