See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

# Structural Isomers of $C_6H14$ **Step 1: Identify the molecular formula type** $C_6H14$ follows the pattern $C_nH_{2n+2}$ (saturated alkane with no rings or double bonds), so all isomers are hexane variants. **Step 2: Enumerate all possible carbon skeletons** 1. **n-Hexane**: Linear chain — $CH_3-CH_2-CH_2-CH_2-CH_2-CH_3$ 2. **2-Methylpentane**: Methyl branch at position 2 — $CH_3-CH(CH_3)-CH_2-CH_2-CH_3$ 3. **3-Methylpentane**: Methyl branch at position 3 — $CH_3-CH_2-CH(CH_3)-CH_2-CH_3$ 4. **2,2-Dimethylbutane**: Two methyls at position 2 — $(CH_3)_3C-CH_2-CH_3$ 5. **2,3-Dimethylbutane**: One methyl each at positions 2 and 3 — $CH_3-CH(CH_3)-CH(CH_3)-CH_3$ **Step 3: Verify no duplicates** Each structure has a unique carbon skeleton—no symmetry or renumbering produces the same compound. **Answer: 5 structural isomers** ✓ The correct option is **(3) 5**.