See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Solution: Amphipathic Reactivity of Methylamine **Key Concept:** A species behaves as both nucleophile and electrophile when it has: - A lone pair (to act as nucleophile) - A polarizable/electron-deficient site (to act as electrophile) **Analysis of each option:** **(1) $CH_3NH_2$ (Methylamine) ✓** - **Nucleophile:** Nitrogen has a lone pair → attacks electrophilic carbons/protons - **Electrophile:** The $N$-$H$ bonds are polarized; the hydrogen is slightly acidic and can accept electron density from nucleophiles - Can donate H-bonds and accept lone pairs in different reactions **(2) $CH_3OH$** - Nucleophile: Yes (oxygen lone pair) - Electrophile: Only weakly (as H-bond donor), not a typical electrophile **(3) $CH_3CN$** - Nucleophile: No (nitrogen's lone pair is delocalized into $\pi$ system) - Electrophile: Yes (polarized $C \equiv N$) **(4) $CH_3Cl$** - Nucleophile: No (Cl is electronegative, withdraws electrons) - Electrophile: Yes (polarized $C$-$Cl$ bond) **Answer: (1) $CH_3NH_2$** — The N-H group provides both nucleophilic lone pairs and acidic hydrogens, enabling dual reactivity.