See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Solution: π-electron density in benzene ring **Understanding π-electron density:** π-electron density in the benzene ring is maximum when electron-donating groups increase electron concentration in the ring, and minimum when electron-withdrawing groups deplete it. **Analyzing each substituent:** - **(A) $NO_2$ (nitro group):** Strongly electron-withdrawing via resonance (withdraws electrons from ring) $$\text{Ring} \leftarrow \text{NO}_2 \text{ (EWG)}$$ - **(B) $\bar{O}$ (alkoxy/oxygen anion):** Strongly electron-donating via resonance (donates electrons to ring) $$\text{Ring} \rightarrow \bar{O} \text{ (EDG - powerful donor)}$$ - **(C) $NH_2$ (amino group):** Electron-donating via resonance, but weaker than $\bar{O}$ (lone pair on N is less available than negative charge on O) - **(D) $OCH_3$ (methoxy group):** Electron-donating but through O's lone pair; less effective than $\bar{O}$ due to no formal negative charge **Comparison:** $$\text{Electron donation: } \bar{O}^- > NH_2 > OCH_3 > NO_2$$ The oxygen anion ($\bar{O}$) is the **strongest electron donor** due to its negative formal charge and direct resonance contribution to the ring, maximizing π-electron density. **Answer: (B)** ✓