question_answer

In \[Br{{F}_{3}}\] molecule, the lone pairs occupy equatorial positions to minimize :                

A) lone pair-bond pair repulsion only

B) bond pair-bond pair repulsion only

C) lone pair-lone pair repulsion and lone pair-bond pair repulsion

D) lone pair-lone pair repulsion only

Correct Answer: D

Solution :

  In \[\text{Br}{{\text{F}}_{\text{3}}}\]molecule, Br is\[\text{s}{{\text{p}}^{3}}\]d hybrid, but geometry is T-shaped due to distortion of geometry from trigonal-bipyramidal to T-shaped by the involvement of lone pair-lone   pair repulsion. Here \[{{\text{l}}_{\text{p}}}-{{\text{l}}_{\text{p}}}\]repulsion = 0 \[{{\text{l}}_{\text{p}}}-{{\text{b}}_{\text{p}}}\]repulsion = 4 \[{{\text{b}}_{\text{p}}}-{{\text{b}}_{\text{p}}}\]repulsion = 2