Question

The correct orientations of dipoles in pyrrole and pyridine is:

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

Dipole moment shifts in the direction where the more electronegative end is present in the molecule. In case of pyrrole, lone pair is involved in resonance and hence, $N-$ atom adopts positive charge.

But in case of pyridine, lone pair of $N-$ atom is not involved in resonance. So, the electron density is more on $N-$ atom. Hence, the direction of dipole moment is opposite to pyrrole in case of pyridine.

Resonating structures of pyridine is shown below: