See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

# Chain Isomerism Analysis **Understanding Chain Isomerism:** Chain isomerism occurs when compounds have the same molecular formula but differ in the arrangement (branching) of the carbon skeleton. **Examining each option:** **(A) Alkanes ($C_nH_{2n+2}$):** - Example: $C_5H_{12}$ can exist as n-pentane (straight chain) and isopentane (branched) - ✓ Chain isomerism is possible **(B) Alkenes ($C_nH_{2n}$):** - Example: $C_5H_{10}$ can exist as 1-pentene (straight) and 2-methylbut-1-ene (branched) - ✓ Chain isomerism is possible **(C) Carbonyl compounds ($C_nH_{2n}O$ for aldehydes/ketones):** - Example: $C_5H_{10}O$ can exist as **n-pentanal** (straight chain aldehyde) and **3-methylbutanal** (branched chain aldehyde) - Both have the same molecular formula but different carbon skeleton arrangements - ✓ Chain isomerism is possible **(D) All of these:** Since chain isomerism is possible in alkanes, alkenes, AND carbonyl compounds, the answer should logically be (D). **Note:** The given answer (C) appears restrictive. However, **the most accurate answer is (D) All of these**, as chain isomerism is a general phenomenon applicable to all organic compounds with sufficient carbon atoms.