Question

Why does the reactivity of nitrogen differ from phosphorus?

Answer 1

1. Nitrogen is chemically less reactive. This is because of the high stability of its molecule, N₂.
2. In N₂, the two nitrogen atoms form a triple bond. This triple bond has very high bond strength, which is very difficult to break.
3. It is because of nitrogen’s small size that it is able to form pπ-pπ bonds with itself.
4. This property is not exhibited by atoms such as phosphorus. Thus, phosphorus is more reactive than nitrogen.

Answer 2

1. Nitrogen is much less reactive than phosphorus because of the very high bond dissociation enthalpy (941.4 kJ mol⁻¹) of the N=N triple bond found in the N₂ molecule.
2. The bond dissociation enthalpy of the phosphorus molecule (P₄), which has P-P single bonds, is significantly lower (201.6 kJ mol⁻¹).