The molecular weight (molecular mass) of the gas is:
According to Avogadro's hypothesis equal volumes of gas, measured under the same pressure and temperature conditions, will contain the same number of particles. From this hypothesis, a series of laws is derived that leads to the definition of mol and molar volume.
The molar volume of a gas is the volume occupied by one mole of said gas under certain conditions of pressure and temperature. We must remember that under normal conditions (i.e., pressure equal to
Therefore, if we have a
if we assume that we are in normal conditions.
Knowing this, we can find the molecular mass by dividing the mass of gas between the number of moles: