Question

Which of the following set of molecules will have zero dipole moment?

• A. Nitrogen trifluoride, beryllium difluoride, water, 1,3-dichlorobenzene
• B. Boron trifluoride, beryllium difluoride, carbon dioxide, 1,4- dichlorobenzene
• C. Ammonia, beryllium difluoride, water, 1,4-dichlorobenzene
• D. Boron trifluoride, hydrogen fluoride, carbon dioxide, 1,3-dichlorobenzene

Answer 1

The correct option is B Boron trifluoride, beryllium difluoride, carbon dioxide, 1,4- dichlorobenzene

Symmetrical molecules have zero dipole moment.
$B{F}_3,Be{F}_2,C{O}_2,\text{and}$ 1,4-dichlorobenzene all have symmetrical structure.

Hence, they have zero dipole moment.
Therefore, option (B) is the correct answer.