Sodii Phosphas. Sodium Phosphate. Na3Hpo4+l2H2O= 357.32. Synonym. - Sodium Orthophosphate.

Source

Digest Bone Ash with Sulphuric Acid; Acid Calcium Phosphate is formed. Ca3(Po4)2+2H2So4=CaH4(Po4)2+ 2CaSo4. Filter and add Sodium Carbonate to the solution. CaH4(Po4)2+Na2Co3=Na2Hpo4+-H2O+Co2+CaHpo4. The filtrate requires to be evaporated and the salt is obtained by crystallization.

Characters

Large, colorless, monoclinic prisms, odorless, and having a cooling saline taste. The crystals effloresce on exposure to the air, and gradually lose 5 molecules of their water of crystallization. Solubility. - In 5 parts of water.

Impurities

Lime phosphate sulphates and carbonates.

Sodium Phosphate is used to prepare Ferri Phosphas Solubilis.

Dose, 5 gr. to 1 oz .; .30 to 30. gm.