555. Ammonium Sulfate

Nomenclature

CAS number: 7783-20-2
Sulfuric acid ammonium salt (1:2); diammonium sulfate; mascagnite.
H8N2O4S; mol wt 132.14.
H 6.10%, N 21.20%, O 48.43%, S 24.27%.
(NH4)2SO4.

Description and references

Prepn: Gmelins, Ammonium (8th ed.) 23, 261-280 (1936). Manuf: Faith, Keyes & Clark's Industrial Chemicals, F. A. Lowenheim, M. K. Moran, Eds. (Wiley-Interscience, New York, 4th ed., 1975) pp 103-108. Review: Call, “Ammonium Sulfate” in Mellor's Vol. VIII, Supplement I, Nitrogen (part 1) 473-505 (1964). Solubility studies: A. C. D. Rivett, J. Chem. Soc. 121, 379 (1922); R. M. Caven, T. C. Mitchell, ibid. 125, 1428 (1924).

Properties

Odorless, orthorhombic crystals or white granules. d 1.77. Dec above 280°. One g sol in about 1.5 ml water. Soly in water (g (NH4)2SO4 per 100 g of satd soln): 41.22 (0°); 43.47 (25°); 50.42 (100°) (Rivett). Soly in water (g/100 g H2O): 70.6 (0°); 76.7 (25°); 103.8 (100°) (Caven, Mitchell). Insol in alcohol, acetone. The pH of 0.1 molar aq soln 5.5.

Use

Manuf ammonia alum; in the manuf of H2SO4 to free it from nitrogen oxides; analytical uses; freezing mixtures, flameproofing fabrics and paper; manuf viscose silk; tanning, galvanizing iron; in fractionation of proteins; as fertilizer.