Key idea: Dipole moment + bond polarity

• CH₃CN (acetonitrile)
  Structure: CH₃–C≡N
  Strongly polar due to C≡N (nitrile group), which has a large electronegativity difference and linear structure → strong net dipole.
• CH₃OH (methanol)
  Structure: CH₃–OH
  Polar due to O–H and C–O bonds, but overall dipole is slightly less compared to nitrile.

Final order of polarity:

CH₃CN > CH₃OH

Reason:

• The C≡N group in CH₃CN creates a stronger dipole moment (~3.9 D)
• Methanol has ~1.7 D, so comparatively less polar.

Extra insight (important for exams):

• CH₃OH shows hydrogen bonding → higher boiling point
• CH₃CN is more polar (dipole-wise) but no H-bonding like alcohols

• Polarity (dipole moment):
  CH₃CN > CH₃OH
• Boiling point:
  CH₃CN (≈82°C) > CH₃OH (≈65°C)