See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

# Analysis of Isomerism **Step 1: Identify the molecular formulas** - Structure 1: $CH_3-CH_2-CH=CH_2$ → $C_4H_8$ - Structure 2: $CH_3-C(=CH_2)-CH_3$ → $C_4H_8$ Both have the same molecular formula, so they are isomers of some type. **Step 2: Check the carbon skeleton** - Structure 1: Linear chain of 4 carbons (C-C-C=C) - Structure 2: Also 4 carbons, but arranged as (C-C(=C)-C) — still a continuous 4-carbon chain Both have the **same carbon chain length**, ruling out chain isomerism. **Step 3: Identify the difference** - Structure 1: Double bond is between C3 and C4 (terminal position) — **but-1-ene** - Structure 2: Double bond is between C2 and C3 (internal position) — **but-2-ene** The position of the double bond differs while the carbon skeleton remains unchanged. **Step 4: Conclusion** These are **position isomers** (functional group isomers with respect to the double bond position), not chain isomers. **The answer is (2) — Position isomers**