Question

In ${\mathrm{BrF}}_3$ 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

Answer 1

The correct option is C

Lone pair – lone pair repulsion and lone pair-bond pair repulsion

Explanation for the Correct Option:

option(C): Lone pair – lone pair repulsion and lone pair-bond pair repulsion

• In the${\mathrm{BrF}}_3$molecule,$\mathrm{Br}\mathrm{is}{\mathrm{sp}}^3\mathrm{d}$ hybridized and has its geometry that is T-shaped.
• This is due to the distortion of the geometry of the T-shaped trigonal bipyramid which is a result of the lone pair-lone pair repulsion, for which the figure can be shown as follows;

• From the given shape of the ${\mathrm{BrF}}_3$molecule, we can say that it has, 0 Lone pair-lone pair repulsion along with 4 Lone pair-bond pair repulsion and 2 Bond pair-bond pair repulsion.
• Here the lone pairs occupy equatorial positions to minimize Lone pair – lone pair repulsion and lone pair-bond pair repulsion.

Explanation for the inCorrect Option:

option(A):Lone pair-bond pair repulsion only

• The presence of lone pair in the equatorial position is due to minimizing both Lone pair – lone pair repulsion and lone pair-bond pair repulsion.
• Hence, the given option does not satisfy the correct concept.

option(B): Bond pair-bond pair repulsion only

• To minimize both Lone pair – lone pair repulsion and lone pair-bond pair repulsion, the lone pair is present in the equatorial position.
• Hence, the option is an incorrect one.

option(D): Lone pair – lone pair repulsion only

• The presence of lone pair in the equatorial position is not due to only minimizing the repulsion between the Lone pair – lone pair interaction.
• Hence the given option does not coincide with the correct Option.

Hence, In ${\mathrm{BrF}}_3$ molecule, the lone pairs occupy equatorial positions to minimize: Lone pair – lone pair repulsion and lone pair-bond pair repulsion.