question_answer

Which of the following has maximum dipole moment?

A)  \[NC{{l}_{3}}\]                 

B)  \[NB{{r}_{3}}\]

C)  \[N{{H}_{3}}\]                 

D)  \[N{{I}_{3}}\]

Correct Answer: C

Solution :

                Electronegativity difference between \[N(3.0)\]and \[Cl\,(3.0)\] is zero and hence \[N-Cl\] bonds are non-polar. As a result, the overall dipole moment of \[NC{{l}_{3}}\] molecule and its direction is just the dipole moment of the lone pair of electrons. On the other hand,\[N-Br\,(3.0-2.8),\] \[N-I\,(3.0-2.5)\] and \[N-H\,(3.0-2.1)\] are polar and hence contribute towards the overall dipole moment of the respective molecules. Since the EN difference is highest in case of \[N-H\]bonds, therefore, \[N{{H}_{3}}\] has the highest dipole moment.