(a)What happens when white phosphorus is heated with concentrated `NaOH` solution in an inert atmosphere of `CO_(2)`?
(b)Draw the structure of white phosphorus and red phosphorus. Which one of these two types of phosphorus, is more reactive and why ?

Explanation

(a)White phosphorus reacts with `NaOH` to from phosphine.
`underset("Phosphorus")(P_(4)+3NaOH)+3H_(2)O underset(CO_(2)"atmosphere") overset("Heat") to underset("Phosphine")(PH_(3))+underset({:("Sodium"),("hypophosphite"):})(3NaHPO_(2))`
(b)Both white and red phosphorus consist of `P_(4)` tetrahedra. In white phosphorus, the various `P_(4)` molecules are held together by weak van der Waals forces of attraction.In each `P_(4)` molecule, the `PPP` angle is only `60^(@)` which is much smaller than the normal tetrahedral angle of `109^(@)28'`.As a result, there is considerable angle strain.Due to weaker forces of attraction and considerable angle strain, white phosphorus is very reactive.
In contrast in red phosphorus, there `P_(4)` tetrahedra are joined together through covalent bonds to give polymeric structure.
Since it is difficult to break strong covalent bonds as compared to weak van der Waals forces of attraction. therefore, white phosphorus is more reactive than red phosphorus.

white p and red p