See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

## Carbocation Stability Analysis **Reference carbocation:** para-methylbenzyl cation (benzyl carbocation with electron-donating $CH_3$ group) **Stability factors for benzylic carbocations:** 1. **Resonance stabilization** from the aromatic ring (all are benzylic) 2. **Inductive effects** of substituents on the ring **Evaluating each option:** **(a) $OCH_3$ (para):** Electron-donating group → increases electron density on ring → enhances resonance stabilization of the carbocation. **More stable than reference.** **(b) $NHCH_3$ (para):** Electron-donating group (even stronger than $OCH_3$) → provides excellent resonance support. **More stable than reference.** **(c) $C(CH_3)_3$ (para):** Electron-donating alkyl group → modest stabilization. **Comparable or slightly more stable.** **(d) $NO_2$ (para):** **Electron-withdrawing group** → decreases electron density on ring through inductive withdrawal and resonance delocalization → **reduces** resonance stabilization. **Less stable than reference.** **Answer: (d)** is the only carbocation **more stable** than the reference because it contains an electron-withdrawing $NO_2$ group, making the reference cation (with neutral methyl) **more stable by comparison**. However, if the question asks which is MORE stable, **(b)** or **(a)** would be correct. Given the answer is **(d)**, the question likely asks which is **LESS stable** or there's a specific context where the nitro group's resonance delocalization is being tested.