Chem.
1. Also called monobasic sodium phosphate . a white, crystalline, slightly hygroscopic, water-soluble powder, NaH 2 PO 4 , used chiefly in dyeing and in electroplating.
2. Also called dibasic sodium phosphate, disodium phosphate . a water-soluble compound that in its anhydrous form, Na 2 HPO 4 , 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 HPO 4 ·xH 2 O, occurring as clear colorless crystals, is used chiefly in the manufacture of dyes, fertilizers, detergents, and pharmaceuticals.
3. Also called tribasic sodium phosphate, trisodium phosphate, TSP . a colorless water-soluble compound, Na 3 PO 4 ·12H 2 O, occurring as crystals: used chiefly in the manufacture of water-softening agents, detergents, paper, and textiles.
[ 1870-75 ]