Na2HPO3

Sodium hydrogen phosphate, also known as disodium phosphate or dibasic sodium phosphate, has the chemical formula Na2HPO3. It is a salt of sodium and the hydrogen phosphate ion. This compound typically exists as a white, crystalline powder. It is soluble in water but insoluble in alcohol. When dissolved in water, Na2HPO3 forms an alkaline solution due to the hydrolysis of the hydrogen phosphate ion. Na2HPO3 can exist in various hydrated forms, with the anhydrous form and the dihydrate being common.

In its anhydrous form, Na2HPO3 has a molar mass of approximately 141.96 g/mol. The dihydrate form, Na2HPO3·2H2O, has a molar mass of about 178.00 g/mol. Sodium hydrogen phosphate is produced by reacting phosphoric acid with sodium hydroxide or sodium carbonate. It is an important industrial chemical and is used in various applications.

Industrially, Na2HPO3 finds use as a buffer, a food additive (E339), a water softener, and in the production of other phosphate salts. In the food industry, it acts as an emulsifier, a thickening agent, and a nutrient supplement. It is also employed in detergents and as a metal treatment agent. Its ability to sequester metal ions contributes to its effectiveness in water treatment and cleaning applications.