Question

Which of the following is correct representation of the reaction when $B{F}_3$ reacts with ammonia?

• A. (1) is incorrect and (2) is correct
• B. (1) is correct and (2) is incorrect
• C. Both (1) and (2) are correct
• D. Both (1) and (2) are incorrect

Answer 1

The correct option is B (1) is correct and (2) is incorrect

As $B{F}_3$ is a Lewis acid and $N{H}_3$ is a Lewis base, $N{H}_3$ donates its lone pair to $B{F}_3$ and forms a dipolar bond. $N{H}_3$ gets a positive formal charge and $B{F}_3$ gets a negative formal charge and adduct is formed.

$B{F}_3+N{H}_3⟶F_{3}BN{H}_3\left(adduct\right)$

In (1), $B{F}_3$ is accepting the lone pair while in (2), $N{H}_3$ is accepting the lone pair.

Thus, (1) is correct and (2) is incorrect.