Laboratory Preparation of Phosphorus Trioxide

Phosphorus trioxide (P2O3 or P4O6is obtained by the combustion of phosphorus in a limited supply of air.

4P + 3O2 → 2P2O3


Physical properties

  • It is a white waxy substance
  • It has a garlic odour.

Chemical properties

  1. It reacts with cold water, gives phosphorus acid.

P2O3 +3H2O → 2H3PO3

  1. It reacts with hot water vigorously to form inflammable phosphine.

2P2O3 + 6H2O → PH3 ↑ + 3H3PO4