See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

**Analysis of Common Characteristics:** Both cis-2-butene and trans-2-butene are structural isomers with the same molecular formula $C_4H_8$ and identical carbon-carbon double bond positions. **Evaluating Each Option:** **(A) Boiling Point (B.P.):** - cis-2-butene: B.P. = 3.7°C - trans-2-butene: B.P. = 0.9°C - ✗ Different B.P. values due to different molecular shapes and intermolecular forces **(B) Dipole Moment:** - cis-2-butene: polar (μ ≠ 0) due to asymmetric arrangement of substituents - trans-2-butene: nonpolar (μ = 0) due to symmetry canceling dipoles - ✗ Clearly different **(C) Heat of Hydrogenation:** $$C_4H_8 + H_2 \rightarrow C_4H_{10} \text{ (butane)}$$ - Both isomers produce the **same product** (butane) - Both release approximately **−30.3 kJ/mol** (same magnitude) - The heat released depends only on breaking the C=C bond strength, which is identical in both isomers - ✓ **Same value** **(D) Product of Hydrogenation:** - Both produce n-butane (same product) — but this is actually a consequence, not a characteristic property in the traditional sense **Answer: (C)** Heat of hydrogenation is the best common characteristic because both isomers undergo the same hydrogenation reaction releasing identical amounts of energy.