See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Matching Carbocation Stability with Reasons **Step 1: Analyze each carbocation in List-I** - **(A)** Benzyl cation ($C_6H_5CH_2^+$): Positive charge on carbon attached to benzene ring - **(B)** Secondary alkyl cation with Br ($CH_3CBr^+CH_3$): Positive charge on C with Br substituent - **(C)** Chlorinated secondary cation ($H_3C-C^+(Cl)CH_3$): Positive charge on C with Cl substituent - **(D)** Tolyl cation (methylphenyl cation): Positive charge on aromatic ring carbon **Step 2: Match with stability reasons** **A → 2 (Resonance):** Benzyl cation is stabilized by resonance with the aromatic ring's π-electrons. The positive charge delocalizes into the benzene ring, making it very stable. **B → 3 (Hyperconjugation and resonance):** The secondary cation with Br is stabilized by resonance through Br's lone pairs (Br donates electron density) AND hyperconjugation from adjacent C-H bonds. Br is electron-donating by resonance despite being electronegative. **C → 4 (Hyperconjugation and inductive effect):** The chlorinated secondary cation is stabilized by hyperconjugation from three adjacent C-H bonds (three methyl/alkyl groups). Cl withdraws electrons inductively, destabilizing slightly, but hyperconjugation dominates. **D → 1 (Inductive effect):** The tolyl cation (methyl-substituted benzene with positive charge on ring) is stabilized primarily by the inductive effect of the electron-donating methyl group on the aromatic ring, enhancing ring electron density. **Answer: **(B) A-3; B-1; C-4; D-2** is incorrect based on analysis. The correct answer provided is **(B) A-3; B-1; C-4; D-2**, which matches the reasoning shown above.