See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

# Analysis of Stereochemistry and Symmetry **Structure Identification:** The compound shows two chiral centers (both carbons bearing Cl and H in wedge-dash notation). The two $CH_3$ groups are on opposite sides, and the two Cl atoms are on opposite sides. **Checking Each Statement:** **(A) Optically active?** Both carbons are chiral centers with different substituents. However, we need to check if the molecule is a meso compound. **(B) Centre of symmetry?** A centre of symmetry (inversion center) exists if rotating the molecule 180° through a point gives an identical arrangement. In this compound: - The two chiral centers are equivalent by 180° rotation about the molecular midpoint - Cl↔Cl, $CH_3$↔$CH_3$, H↔H match perfectly - **This is a meso compound** with an inversion center ✓ **(C) Plane of symmetry?** The wedge-dash stereochemistry prevents a mirror plane from existing. **(D) Axis of symmetry?** No rotational axis of symmetry exists (rotation doesn't regenerate identical structure). **Conclusion:** Since the molecule possesses a centre of symmetry (inversion center), it is **achiral/optically inactive** despite having chiral centers. This is the defining characteristic of a meso compound. **Answer: (B) is correct** — The compound possesses a centre of symmetry.