The full solution can be found in the image attached. Graham's law was applied to the problem. The rate of diffusion of a gas is inversely proportional to its molar mass or vapour density. Molar mass= 2vapour density
This means for every number of Carbon (C) atoms, there are twice as many Hydrogen (H) atoms with an additional two added onto that.
Therefore, if there is one Carbon Atom, and we multiply that by two, and then add an additional two, we get 4 Hydrogen atoms, so CH4, which is our first Formulae
Secondly, if we have eight Carbon Atoms, and we multiple that by two (16), and then add an additional two, we get 18 Hydrogen atoms, so C8H18, which is our second Formulae
The other Formulas do not follow this 'General Formula'
