Question

The $BC{{l}_{3}}$ is a planar molecule whereas $NC{{l}_{3}}$ is pyramidal, because:

• A. nitrogen atom is smaller than boron atoms
• B. $B-Cl$ bond is more polar than $N-Cl$ bond.
• C. $N-Cl$ bond is more covalent than $B-Cl$ bond
• D. $BC{{l}_{3}}$ has no lone pair but $NC{{l}_{3}}$ has a lone pair of electrons

Answer 1

Answer: (D)

$BC{{l}_{3}}$ has no lone pair but $NC{{l}_{3}}$ has a lone pair of electrons

Answer 2

In boron trichloride, boron is $s{{p}^{2}}$ hybridised and there is no lone pair on boron while in nitrogen. It is $s{{p}^{3}}$ hybridised and there is a lone pair of electron in nitrogen. Hence, due to this reson $BC{{l}_{3}}$ is a planer molecule and $NC{{l}_{3}}$ is a pyramidal molecule.