Molecules with Zero Dipole Moment

The total number of molecules with zero dipole moment among CH₄, BF₃, H₂O, HF, NH₃, CO₂ and SO₂ is ________.

Correct Answer: 3

Explanation

Molecules having zero dipole moment must be symmetrical so that individual bond dipoles cancel out.

• CH₄ → Tetrahedral, symmetrical → Zero dipole
• BF₃ → Trigonal planar, symmetrical → Zero dipole
• CO₂ → Linear, symmetrical → Zero dipole
• H₂O → Bent → Non-zero dipole
• HF → Polar bond → Non-zero dipole
• NH₃ → Pyramidal → Non-zero dipole
• SO₂ → Bent → Non-zero dipole

Hence, total molecules with zero dipole moment = 3

Related JEE Main Chemical Bonding Questions