Also called dibasic sodium phosphate, disodium phosphate
. a water-soluble compound that in its anhydrous form, Na 2
, occurring as a white, crystalline, hygroscopic powder, is used chiefly in the manufacture of ceramic glazes, enamels, baking powder, and cheeses, and that in its hydrated form, Na 2
O, occurring as clear colorless crystals, is used chiefly in the manufacture of dyes, fertilizers, detergents, and pharmaceuticals.