Write down the molecular and structural formulas of an alkane, the molecule of which contains 8

Write down the molecular and structural formulas of an alkane, the molecule of which contains 8 carbon atoms. Give the formula for the homologue of this alkane, which has one less carbon atom.

The molecular formula of an alkane with 8 carbon atoms is C8H18.

According to this formula, there are 8 isomeric alkanes:
1.n-octane
2.3-methylheptane
3.2-methylheptane
4.4-methylheptane
5. 2,3,3-trimethylpentane
6.2,4-trimethylpentane
7.3-ethylhexane
8,2,3,4-trimethylpentane

The molecular formula of the homologue is C7H16.

9 isomers:
1.n-heptane
2.2-methylhexane
3.3-methylhexane
4.3-ethylpentane
5.2,3-trimethylbutane
6.2-dimethylpentane
7.2,3-dimethylpentane
8. 2,4-dimethylpentane
9.3,3-dimethylpentane