Heptane is `C_(7)H_(16)`
The homologues of heptane are `C_(6)H_(14)` and `C_(8)H_(18)`
i. Molecule of hexane having one quaternary `C` atom:
`overset(1)(CH_(3))-underset(C-2 is 4^(@)C "atom")underset(CH_(3))underset(|)overset(CH_(3))overset(|)(C^(2))-overset(3)(CH_(2))overset(4)(CH_(3))("2,2-Dimethyl butane")`
Molecule of octane having one quaternary `C` atom:
`overset(1)(CH_(3))-underset(C-2 is 4^(@)C "atom")underset(CH_(3))underset(|)overset(CH_(3))overset(|)(.^(2)C)-overset(3)(CH_(2))overset(4)(CH_(2))overset(5)(CH_(2))overset(6)(CH_(3))("2,2-Dimethyl hexane")`
Note: Other structrues with one quaternary may also be formed with octance.
ii. Molecule of hexane having two tertiary `C` atoms
`underset("2,3-Dimethyl butane")(overset(1)(CH_(3))- underset(CH_(3))underset(|)overset(2)(CH)-underset(CH_(3))underset(|)overset(3)(CH)-overset(4)(CH_(3)))`
Where `C-2` and `C-3` are `3^(@)C` atoms.
Molecule of octone having two tertiary `C` atoms:
`underset("2,3-Dimethyl hexane")(overset(1)(CH_(3))- underset(CH_(3))underset(|)overset(2)(CH)-underset(CH_(3))underset(|)overset(3)(CH)-CH_(2).CH_(2).CH_(3))`
`C-2` and `C-3` are `3^(@)C` atoms.