Question

The number of different chain isomers for \( \text{C}_7\text{H}_{16} \) is ______.

Answer 1

Correct Answer: 9

For a hydrocarbon with the molecular formula \( C_7H_{16} \), which is an alkane, we can determine the possible chain isomers by drawing all unique structures with the same molecular formula.

The chain isomers for \( C_7H_{16} \) are as follows:

Straight Chain (Heptane):

\[ \text{CH}_3 - \text{CH}_2 - \text{CH}_2 - \text{CH}_2 - \text{CH}_2 - \text{CH}_2 - \text{CH}_3 \]

Branched Chains (Various Isomers):

• 2-Methylhexane
• 3-Methylhexane
• 2,2-Dimethylpentane
• 2,3-Dimethylpentane
• 2,4-Dimethylpentane
• 3,3-Dimethylpentane
• 3-Ethylpentane
• 2,2,3-Trimethylbutane

Each of these structures represents a distinct arrangement of carbon atoms, satisfying the molecular formula \( C_7H_{16} \).

Conclusion:

There are a total of 9 different chain isomers for \( C_7H_{16} \).