See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

# Identifying Metamers **Metamers** are compounds with the same molecular formula but different positions of a functional group or heteroatom within the carbon chain. ## Analysis of Each Option: **(1)** $CH_3\text{-}O\text{-}CH_2CH_2CH_3$ and $CH_3\text{-}CH_2\text{-}O\text{-}CH_2\text{-}CH_3$ - Both have formula $C_4H_{10}O$ ✓ - Oxygen at different positions in the chain → **Metamers** ✓ **(2)** $C_2H_5\text{-}O\text{-}C_2H_5$ and $CH_3CH_2CH_2CH_2OH$ - First: $C_4H_{10}O$ | Second: $C_4H_{10}O$ (same formula) - But these are **isomers of different functional groups** (ether vs alcohol), not metamers ✗ **(3)** $CH_3\text{-}O\text{-}C_2H_5$ and $CH_3\text{-}CH_2\text{-}O\text{-}CH_3$ - Both have formula $C_3H_8O$ ✓ - Oxygen at different positions → **Metamers** ✓ **(4)** $CH_3\text{--}CH_3$ and $CH_3\text{-}CH_2\text{--}H$ - These represent the same molecule (ethane) written differently ✗ - Not different compounds ## Answer: **Only options (1) and (3) contain true metamers** — they have identical molecular formulas with the heteroatom (oxygen) at different positions along the carbon chain.