question_answer

Which of the following molecules has the maximum dipole moment?

A) \[C{{O}_{2}}\]

B) \[C{{H}_{4}}\]    

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

D) \[N{{F}_{3}}\]

Correct Answer: C

Solution :

\[C{{O}_{2}}\] and \[C{{H}_{4}}\] have zero dipole moment as these are symmetrical in nature. Between \[N{{H}_{3}}\] and \[N{{F}_{3}}\], \[N{{H}_{3}}\] has greater dipole moment, though in \[N{{H}_{3}}\] and \[N{{F}_{3}}\] both, N possesses one lone pair of electrons. This is because in case of \[N{{H}_{3}}\] the net \[N-H\] bond dipole is in the same direction as the direction of dipole of lone pair, but in case ofNF3, the direction of net bond dipole moment of three \[-N-F\] bonds is opposite to that of the dipole moment of the lone pair.
[a]	[b]
[c]	[d]