Question

wolecoles is Mast Altoust A/

Answer 1

A. Pyridine B. Pyrrole D. Indole

I think A and C both are pyridine (same compound) based on the structure.

Generally sp² hybridised nitrogen is less basic than sp³ hybridised N atom that means sp² hybridised nitrogen is more electronegative than sp³ hybridised N atom. but above the three compound sp² hybridised nitrogen atom,

but in pyrrole the lone pair of nitrogen atom conjugate with double bond also indole compound Nitrogen lone pair also conjugate in the ring but pyridine the lone pair is not conjugate in the ring.so the pyridine lone pair is easily available. second when compared pyrrole and Indole, Indole N lone pair very extent of conjugation.so pyrrole is More basic when compared to Indole.

so the order of Basicity is

Pyridine Pyrrole Indole

A B D

so the order of Aromaticity is

Indole Pyridine Pyrrole