Exercise 1 Question 8
What happens when white phosphorus is heated with concentrated NaO Hsolution in an inert atmosphere of CO2?
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 stable and therefore more reactive than other allotropic forms of Phosphorus. On heating with concentrated NaOH in an inert environment of CO2 following 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.
