Important allotropic forms of phosphorus are white phosphorus, red phosphorus and black phosphorus. Among these which allotropic form is more reactive ? Why ?

Explanation

White phosphorus is the most reactive because of the following two reasons :
(i) White phosphorus consists of `P_(4)` molecules which are held together by weak van der Walls forces of attraction.
(ii) The `P_(4)` molecules have considerable angle strain because in them PPP angle is just `60^(@)`.
Therefore, due to considerable angle strain and weaker forces of attraction, white phosphorus is most reactive.