Question

Why $NC{l}_3$ and $PC{l}_3$ are hydrolysed differently?

Answer 1

Hydrolysis of $N{Cl}_3$-

$N{Cl}_3+H_{2}O⟶N{H}_3+3HOCl$

Hydrolysis of $P{Cl}_3$-

$P{Cl}_3+H_{2}O⟶H_{3}P{O}_3+HCl$

In $N{Cl}_3$, nitrogen and chlorine have similar electronegativities resulting in non-polar bonds. Nitrogen doesn’t have empty d-orbitals, thus the hydrolysis takes place with the donation of lone pair of electron by nitrogen to the hydrogen atom of water.

In $P{Cl}_3$, phosphorous is less electronegative than chlorine due to which they form a polar bond and thus the positive polar charge on phosphorous attacks the lone pair of electrons on water molecule to give different products.