Question

Which among the following is the least basic?

• A. $NC{l}_3$
• B. $NB{r}_3$
• C. $N{I}_3$
• D. $N{F}_3$

Answer 1

The correct option is D $N{F}_3$

$N{F}_3$ is the least basic because fluorine is the most electronegative and it will attract the lone pairs of the nitrogen atom and thus the electrons will be less available for donation. As the size of halide ion increases the electronegativity of halide ion decreases and the basic character of $N{X}_3$ increases.