Question

When $B{F}_3$ is treated with $N{H}_3$,

• A. Hybridization of $N$ is changed
• B. Hybridization of $B$ is changed
• C. Hybridization of both $N$ and $B$ are changed
• D. Cannot predict

Answer 1

The correct option is B Hybridization of $B$ is changed

$B{F}_3+:N{H}_3\to [F_{3}B\leftarrow :N{H}_3]$

Here, the hybridization of $N$ ($s{p}^3$) is the same before and after the reaction since the steric number is 4 before and after the reaction. But the hybridization of $B$ is changed from $s{p}^2$ to $s{p}^3$ because of the increase in the steric number from 3 to 4.