JEE MainChemistryp Block Elements (Group 15, 16, 17 & 18)
At room temperature, dinitrogen ( N₂ ) is chemically inert, whereas white phosphorus ( P₄ ) is highly reactive and spontaneously catches fire in air. The primary reason for this stark difference in reactivity is:
Options
- ANitrogen is a gas at room temperature while white phosphorus is a solid.
- BNitrogen has a significantly higher electronegativity than phosphorus.
- CNitrogen forms a very strong p -p triple bond, whereas phosphorus forms single bonds with significant angle st
- DNitrogen lacks vacant d-orbitals in its valence shell, whereas phosphorus has them available for bonding.
Correct answer
C. Nitrogen forms a very strong p -p triple bond, whereas phosphorus forms single bonds with significant angle st
Step-by-step solution
Dinitrogen ( N₂ ) exists as a diatomic molecule with a triple bond ( N N ) formed by p -p multiple bonding. Because of its very high bond dissociation enthalpy, it is highly unreactive at room temperature. On the other hand, phosphorus cannot form stable p -p multiple bonds due to its larger atomic size. It exists as a discrete tetrahedral P₄ molecule with P-P single bonds. The P₄ molecule is highly strained (bond angle 60^ ), making it highly reactive and prone to catching fire in air. Therefore, the primary reaso