RXMARINE CHEMICAL TAG::
Phosphoryl chloride (commonly called phosphorus oxychloride) is a colourless liquid with the formula POCl3. It hydrolyses in moist air releasing phosphoric acid and fumes of hydrogen chloride. It is manufactured industrially on a large scale from phosphorus trichloride and oxygen or phosphorus pentoxide.
Phosphorous acid, H3PO3, is the acid that forms when P4O6 reacts with water. For preparing a small amount of the acid in a laboratory, it is more convenient to carefully hydrolyze PCl3.