See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

# Analysis of Isomerism in $C_5H_{12}O$ **Step 1: Identify the degree of unsaturation** $$\text{DBE} = \frac{2(5) + 2 - 12}{2} = 0$$ No rings or double bonds → saturated compound. **Step 2: Determine possible structures** With molecular formula $C_5H_{12}O$, the oxygen can be incorporated as: - An $-OH$ group (alcohol) - An $-O-$ group (ether) **Step 3: Check for position isomerism** For alcohols with the pentane backbone, the $-OH$ group can attach at different positions: - $CH_3CH_2CH_2CH_2CH_2OH$ (pentan-1-ol) - $CH_3CH_2CH_2CH(OH)CH_3$ (pentan-2-ol) - $CH_3CH_2CH(OH)CH_2CH_3$ (pentan-3-ol) These are **position isomers** — same carbon skeleton, different functional group positions. **Step 4: Verify chain/functional isomerism doesn't apply here** - **Chain isomerism** would require different carbon skeletons (e.g., branched vs. linear), but $C_5H_{12}O$ primarily shows position isomerism for alcohols. - **Functional isomerism** (alcohol vs. ether) exists, but the question emphasizes the most prominent isomerism type. **Answer: (A) Position isomerism** The $-OH$ functional group can occupy different positions on the same carbon chain, creating distinct isomers.