The correct relationship between molecular mass (M) and vapour (VD) is

The relation between molecular weight (M) and vapour density (VD) is :

The correct relationship between molarity (M) and molality (m) is (d = density of the solution, in "KgL"^(-1) , M_2 = molar mass of the solute in kg "mol"^(-1) )

What is the relationship between molecular mass and vapour density ?

Derive the relationship between relative molecular mass and Vapour density.