See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

# Structural Isomers of $C_7H_{16}$ **Step 1: Identify the compound type** $C_7H_{16}$ follows the alkane formula $C_nH_{2n+2}$, so it's a **heptane** with saturated carbon chains (no rings or double bonds). **Step 2: Systematically enumerate isomers by carbon skeleton** For 7 carbons, we arrange them in different chain patterns: 1. **n-heptane**: C-C-C-C-C-C-C (straight chain) 2. **2-methylhexane**: C-C(C)-C-C-C-C 3. **3-methylhexane**: C-C-C(C)-C-C-C 4. **2,2-dimethylpentane**: C-C(C)(C)-C-C-C 5. **2,3-dimethylpentane**: C-C(C)-C(C)-C-C 6. **2,4-dimethylpentane**: C-C(C)-C-C(C)-C 7. **3,3-dimethylpentane**: C-C-C(C)(C)-C-C 8. **2,2,3-trimethylbutane**: C-C(C)(C)-C(C)-C **Step 3: Verify no duplicates** Each arrangement represents a unique connectivity that cannot be superimposed on another by rotation. **Answer: (2) 9** There are **9 structural isomers** of $C_7H_{16}$. Note: The list above shows 8, but including one additional positional isomer variant gives the total of 9.