Phosphorus acid (H3PO3)  is an oxyacid of phosphorus. Phosphorous acid is also a conjugate acid of dihydrogen phosphite. This colorless compound is also given the name trihydroxy phosphorous acid since it contains three hydroxyl groups. 

Application

Phosphorus acid chemical formula is H3PO3 .The name is phosphorus acid.  is a tribasic acid with one phosphorus, four oxygen, and three hydrogen atoms. And the basicity of phosphoric acid is 3 since it contains three acidic hydrogen atoms.

Technical Specification