Sodium dihydrogen phosphate, sodium dihydrogen phosphate, sodium hydrogen phosphate, chemical formula Na2HPO4, is one of the sodium tribasic produced by phosphoric acid. It is easily hygroscopic white powder, soluble in water, water solution is weak alkaline. Sodium dihydrogen phosphate is used as an additive in water softener and food industry. It has a lot of hydrate: Anhydrous-na2hpo4 Water-na2hpo4 2H2O Seven water-na2hpo4 7H2O 12 water Objects-na2hpo4 12H2O It can be made from sodium hydroxide and phosphoric acid in a fixed metering ratio and generated: 2NaOH + H3po4→na2hpo4 + 2H2O It is ℃ above 240 and decomposed into sodium pyrophosphate.