question_answer

Which one of the following molecules, has zero dipole moment?

A)  \[B{{F}_{3}}\]                   

B)                                         \[N{{H}_{3}}\] 

C)         \[C{{H}_{2}}C{{l}_{2}}\]

D)         \[S{{O}_{3}}\]

Correct Answer: A

Solution :

\[B{{F}_{3}}\] has zero dipole-moment as it is a planar molecule with F?B?F bond angle \[120{}^\circ \]. Hence, bond moments cancel each other. The resultant dipole moment becomes zero.