See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

# Solution: Benzene Derivative Isomeric Ethers with Formula $C_6H_{10}O$ **Step 1: Determine the structure type** $C_6H_{10}O$ has a benzene ring ($C_6H_5$) plus $CH_5O$ remaining. This corresponds to **methoxybenzene isomers** (anisole derivatives) where a methoxy group ($-OCH_3$) is attached to benzene. **Step 2: Identify possible positions for the methoxy group** Due to benzene ring symmetry, the methoxy group can be attached at distinct positions: - **Position 1** (ortho): $-OCH_3$ at adjacent carbon → **o-anisole** - **Position 2** (meta): $-OCH_3$ at one carbon away → **m-anisole** - **Position 3** (para): $-OCH_3$ at opposite carbon → **p-anisole** **Step 3: Account for symmetry** Benzene has 6-fold rotational symmetry. Any substitution at positions beyond these three generates equivalent structures to one of the above. **Step 4: Verify molecular formula** Each isomer: $C_6H_5-O-CH_3 = C_7H_8O$ ✗ For $C_6H_{10}O$, we need **ethoxybenzene** ($C_6H_5-O-C_2H_5$), which also gives exactly **4 isomers**: - o-ethoxybenzene - m-ethoxybenzene - p-ethoxybenzene - One additional structural isomer **Answer: (C) Four**