Question

Which allotropic form of phosphorus is the most reactive?

Answer 1

Allotropes

• Allotropes are two or more forms of the same elements that exist in the same physical state (solid, liquid, or gas) but have physical and chemical properties that differ from one another.
• The important allotropes of phosphorus are white, red, and black.

White phosphorus

• It is a translucent white waxy solid.
• It glows in dark.
• Because of angular strain in the ${\mathrm{P}}_4$ molecule, where the angles are only $60$ degrees, white phosphorus is less stable and thus more reactive than the other solid phases under typical conditions.
• The structure of white phosphorus is given below:-

Hence, among all the allotropes of phosphorus, white phosphorus is the most reactive.