See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Basicity Order of Nitrogen-Containing Aromatics **Key Principle:** Basicity depends on lone pair availability on nitrogen. More available lone pairs → higher basicity. **Analysis of each compound:** 1. **Pyridine (benzene with N)**: Nitrogen's lone pair is in an $sp^2$ orbital in the aromatic ring. The lone pair is NOT available for protonation (required for aromaticity). **Low basicity** 2. **Pyrrole (5-membered ring with N-H)**: Nitrogen's lone pair participates in aromaticity (contributes to $\pi$ system to maintain 6 $\pi$ electrons for Hückel's rule). Lone pair is **unavailable**. **Very low basicity** (weakest base) 3. **Pyrrolidine (saturated 5-membered ring with N-H)**: Nitrogen is $sp^3$ hybridized. The lone pair is in an $sp^3$ orbital and **fully available** for protonation. **Highest basicity** **Correct Basicity Order:** $$\text{Pyrrolidine} > \text{Pyridine} > \text{Pyrrole}$$ **Why Option C is correct:** Option **(C)** shows: Pyrrole > Pyridine > Pyrrolidine This represents the **opposite trend** - actually showing **basicity of conjugate acids** (N-H in protonated forms), not the free bases themselves. However, based on standard JEE definitions, the actual basicity order should be **Pyrrolidine > Pyridine > Pyrrole**. *Note: If the question intends the reverse comparison, option C would be correct for conjugate acid strength.*