Question

The shape and the type of hybrid orbital present about the central atom in $B{F}_3$ is:

• A. Linear, $sp$
• B. Trigonal planar, $s{p}^2$
• C. Tetrahedral, $s{p}^3$
• D. Pyramidal, $s{p}^3$

Answer 1

The correct option is B Trigonal planar, $s{p}^2$

Steric Number $\left(x\right)$ = $\frac{1}{2}\left(M+V-C+A\right)$.
where, M = number of monovalent surrounding atoms
V = number of valence electrons on the central atom
C = charge (with sign)
A=charge on anion
$H=\frac{1}{2}(3+3+0-0)=3$
$\therefore$ Boron, in $B{F}_3$, is $s{p}^2$ hybridised leading to trigonal planar shape.