Question

The central atoms is ${sp}^2$ hybridized in:

• A. ${BF}_3$ and ${NH}_2^{-}$
• B. ${NO}_2^{-}$ and ${NH}_3$
• C. ${NH}_2^{-}$ and $H_{2}O$
• D. none of these

Answer 1

The correct option is A ${BF}_3$ and ${NH}_2^{-}$

For $s{p}^2$ hybridisation, there must be either $3$ sigma bonds or $2$ sigma bonds 7 one lone pair of electrons in the molecules or ions.

In $B{F}_3$, Number of $\sigma$ bonds= $3$ i.e, $s{p}^2$.

In ${N{H}_2}^{-}$ Number of $\sigma$ bonds= $2$

Number of lone pairs= $1$ {i.e. $s{p}^2$}

$\therefore$ In $B{F}_3$ & ${N{H}_2}^{-}$ the central atom is $s{p}^2$ hybridised.