Question

what happens when phosphorus is heated with strong sodium hydroxide solution

Answer 1

Phosphorus exist in many allotropic forms. The three main forms are:

1) White Phosphorus

2) Red Phosphorus

3) Black Phosphorus

 

White Phosphorus is obtained from phosphorite rock with coke and sand. It consist of P4 units.The four P- atoms lie at the corners of a regular tetrahedron. It is less table and therefore more reactive than other allotropic forms of Phosphorus. On heating with concentrated NaOH in an inert environment of CO2following reaction takes place:

Phosphine (PH3) is formed.This reaction is an example of disproportionation reaction in which oxidation state of phosphorus decreases from 0 in P4 to -3 in PH3,while it increases from 0 in P4 to +1 in NaH2PO2.