What is the relative molecular mass of a gas equal to if the mass of 1 liter of this gas

What is the relative molecular mass of a gas equal to if the mass of 1 liter of this gas, measured at normal conditions, is 1.429 grams?

1 mole of an unknown gas occupies a volume of 22.4 liters under normal conditions. This is one of the consequences of Avogadro’s law.

Therefore, in order to find the mass of 1 mole of gas, it is enough to make a proportion. In proportion, instead of 1 mol, we take the molar volume at once, because we know the mass of a certain volume of gas, not the amount of matter.

22.4 l. gas has a mass of X g.

1 liter of gas has a mass of 1.429 g.

X = (22.4 * 1.429) / 1 = 32 g.

Answer: the relative molar mass of the gas is 32 g / mol. With a high degree of probability, we can say that this is molecular oxygen O2.