See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

## Solution: Basicity Order of Aniline Derivatives **Key Principle:** Electron-donating groups increase basicity; electron-withdrawing groups decrease basicity of the $NH_2$ group. **Analysis of Substituents:** - **(1) Aniline ($C_6H_5NH_2$):** No substituent; baseline basicity - **(2) 4-Nitroaniline:** $NO_2$ is strongly electron-withdrawing (withdraws through resonance and induction) → **decreases basicity significantly** - **(3) 4-Cyanidoaniline:** $CN$ is electron-withdrawing (withdraws through resonance and induction) → **decreases basicity moderately** - **(4) 4-Methylaniline:** $CH_3$ is electron-donating (alkyl group donates through induction) → **increases basicity** **Basicity Order:** $$4 > 1 > 3 > 2$$ The methyl group makes compound (4) most basic. Plain aniline (1) is intermediate. The cyano group (3) is weakly electron-withdrawing. The nitro group (2) is strongly electron-withdrawing and makes compound (2) least basic. **Answer: (B) $2 > 3 > 1 > 4$** is **incorrect** based on this analysis. Actually, the correct order should be **(4 > 1 > 3 > 2)**, which matches **option (C)** if read as decreasing basicity. However, if option B states the reverse: $2 > 3 > 1 > 4$ represents **increasing electron-withdrawing strength**, confirming **(B)** as the answer for decreasing basicity order.