Deduce the molecular shape of `BrF_(3)` on the basis VSEPR theory.

Explanation

No. of electrons in the valence shell of the central Br atom = 7.
No. of electrons provided by three F atoms `= 3 xx 1 = 3`.
Total no. of electrons around the central Br atom = 7 + 3 = 10.
`therefore` Total no. of electron pairs around the central Br atom = 10/2 = 5.
But the no. of bond pairs = 3 (`because` there are three Br-F bonds)
`therefore` No. of lone pairs = 5 - 3 = 2.
On the basis of VSEPR theory, a molecule with three bond pairs and two lone pairs must be T-shapped (i.e., distorted trigonal bipyramidal) as shown.
The tow lone pairs will occupy equatorinal positions to minimze lone pair-lone pair repulsions whic are much stronger than lone pair-bond pair and bond pair-bond pair repulsions. Further, the axial F atoms will be slightly bent towards the equatorial F atom to minimize the lone pair-bond pair repulsions. Therefore, the shape of `BrF_(3)` would be slightly bent T as shown in Figure