542. Ammonium Phosphate, Dibasic

Nomenclature

CAS number: 7783-28-0
Phosphoric acid ammonium salt (1:2); secondary ammonium phosphate; diammonium hydrogen phosphate; Fyrex.
H9N2O4P; mol wt 132.06.
H 6.87%, N 21.21%, O 48.46%, P 23.45%.
(NH4)2HPO4.

Description and references

The grade used medicinally is 98-99% pure. Prepn: Gmelins, Ammonium (8th ed.) 23, pp 422-426 (1936).

Properties

Odorless crystals or cryst powder; saline, cooling taste; gradually loses about 8% NH3 on exposure to air. One gram dissolves in 1.7 ml water, 0.5 ml boil water; practically insol in alcohol, acetone. pH about 8. Keep well closed.

Use

Fireproofing textiles, paper, wood, and vegetable fibers; impregnating lamp wicks; preventing afterglow in matches; flux for soldering tin, copper, brass, and zinc; purifying sugar; in yeast cultures; in dentifrices; in corrosion inhibitors; in fertilizers; in buffers.