question_answer

The molecules \[B{{F}_{3}}\] and \[N{{F}_{3}}\] are both covalent compounds, but \[B{{F}_{3}}\] is non polar whereas \[N{{F}_{3}}\] is polar. The reason for this is

A) atomic size of boron is larger than nitrogen

B) Boron is metal while nitrogen is gas

C) \[B-F\] bonds are non-polar while \[N-F\] bonds are polar

D) \[B{{F}_{3}}\] is planar but \[N{{F}_{3}}\] is pyramidal

Correct Answer: D

Solution :

[d] The shape of \[B{{F}_{3}}\] is trigonal planar  and \[\mu =0\] hence it is non polar. The shape of \[N{{F}_{3}}\] is pyramidal   and \[\mu \ne 0\] hence it is polar.