Title: Hypophosphoric Acid
CAS Registry Number: 7803-60-3
Molecular Formula: H4O6P2
Molecular Weight: 161.98
Percent Composition: H 2.49%, O 59.26%, P 38.24%
Literature References: Prepn from its salts: Salzer, Ann. 187, 322 (1877); 211, 1 (1882). Review: Ohashi, "Lower Oxo Acids of Phosphorus and Their Salts" in Topics in Phosphorus Chemistry Vol. 1, M. Grayson, E. J. Griffith, Eds. (Interscience, New York, 1964) pp 113-187.
Properties: Orthorhombic plates, mp 70° (easily forms a dihydrate, mp 55°), usually available only in aq soln. The aq acid is colorless and odorless; dec on concn at atm pressure. Readily forms crystallizable normal and acid sodium salts.
Melting point: mp 70° (easily forms a dihydrate, mp 55°)
Use: Acid sodium salts in baking powders.