Question

In $Br{F}_3$ molecule, the lone pairs occupy equatorial positions to minimise

• A. lone pair-bond pair repulsion
• B. bond pair-bond pair repulsion
• C. lone pair-lone pair repulsion and lone pair-bond pair repulsion
• D. lone pair-lone pair repulsion

Answer 1

Answer: (C)

In $Br{F}_3$ molecule, $Br$ is $s{p}^{3}d$ hybridised, but its 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, $lp-lp$ repulsion $=0$
$lp-bp$ repulsion $=4$
$bp-bp$ repulsion $=2$