Question

In case of nitrogen, NCl₃ is possible but not NCl₅ while in case of phosphorus, PCl₃ as well as PCl₅ are possible. It is due to
(a) availability of vacant d orbitals in P but not in N
(b) lower electro-negativity of P than N
(c) lower tendency of H-bond formation in P than N
(d) occurrence of P in solid while N in gaseous state at room temperature.

Answer 1

(A) option is correct Phosphorus contains vacant 3d orbital  so it can show +5 and +3 valency forming PCl5 but nitrogen does not contain 2d orbital due to which its valency can be extended to only +3 valency. Forming only NCl3 not NCl5

Answer 2

A) because N shows anamalous behaviour as being first element of 15 group. also due to absence of d orbital it shows only oxidation state of +3 not +5.