Question

What is the relation between 1 mole and vapour density?

Answer 1

Dear student,

Vapour density is the density of a vapour in relation to that of hydrogen. It may be defined as mass of a certain volume of a substance divided by mass of same volume of hydrogen.

vapour density = mass of n molecules of gas / mass of n molecules of hydrogen.
Thus:
vapour density = molar mass of gas / molar mass of H2
vapour density = molar mass of gas / 2.016
vapour density = ~½ × molar mass
(and thus: molar mass = ~2 × vapour density)

Regards