3.2 Recall that alkanes have the general formula CnH2n+2

If you see the post tagged 3.1, a general formula is a formula that all members of a homologous series (in this case, the alkanes) will fit.

Basically (in every single alkane) for every carbon atom there will be twice the amount of hydrogen plus two.
- E.g.: 2 carbons
-         2(2) + 2 hydrogens = 6 hydrogens