See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

# Chain Isomerism Analysis Chain isomerism occurs when a molecular formula can be arranged into compounds with **different carbon skeleton structures** (straight-chain vs branched). ## Checking each option: **(A) $C_3H_8$** — Only 3 carbons available - Only possible structure: straight chain $CH_3-CH_2-CH_3$ (propane) - Cannot form a branched isomer (would need minimum 4 carbons for branching) - **No chain isomerism possible** ✓ **(B) $C_4H_{10}$** — 4 carbons available - Straight chain: butane ($CH_3-CH_2-CH_2-CH_3$) - Branched: isobutane ($\frac{CH_3}{CH_3}-CH-CH_3$) - Shows chain isomerism ✗ **(C) $C_5H_{12}O$** — 5 carbons available - Multiple isomers possible with different carbon skeletons - Shows chain isomerism ✗ **(D) $C_6H_{10}O$** — 6 carbons available - Multiple isomers possible with different carbon skeletons - Shows chain isomerism ✗ ## Conclusion: **Option (A)** will **not show chain isomerism** because $C_3H_8$ has insufficient carbon atoms (minimum 4 needed) to form both straight-chain and branched isomers of the same molecular formula.