Question

Write condensed and bond-line structural formulas for all of the constitutional isomers Practice problem 4.1 with the molecular formula C7H16. (There are a total of nine constitutional isomers.)

Answer 1

The molecular formula C7H16 represents an alkane with 7 carbon atoms with nine constitutional isomers. The condensed and line structural formulas for each isomer are provided.

Step-by-step explanation:

The molecular formula C7H16 represents an alkane with 7 carbon atoms. There are a total of nine constitutional isomers for this molecular formula. Here are the condensed and line structural formulas for each isomer:

1. N-heptane: CH3CH2CH2CH2CH2CH2CH3
2. 2-Methylhexane: CH3CH2CH(CH3)CH2CH2CH3
3. 3-Methylhexane: CH3CH(CH3)CH2CH2CH2CH3
4. 2,2-Dimethylpentane: CH3C(CH3)2CH2CH2CH3
5. 2,3-Dimethylpentane: CH3CH(CH3)C(CH3)CH2CH3
6. 2,4-Dimethylpentane: CH3CH(CH3)CH(CH3)CH2CH3
7. 2,2,3-Trimethylbutane: CH3C(CH3)(CH3)CH2CH2CH3
8. 2,2,4-Trimethylpentane: CH3C(CH3)(CH3)CH(CH3)CH2CH3
9. 3-Ethylpentane: CH3CH2CH2CH(CH3)CH2CH3

Answer 2

See figure 1.

Step-by-step explanation:

In this case have to take into account that all structures must have the formula:
`C_7H_16`. If we remember the general formula for alkanes:
`C_nH_2_n_+_2` if we have "7" carbons (n=7) we will have 16 hydrogens. Therefore all the structures that fit with this formula are alkanes.