509. Ammonium Chloride

Nomenclature

CAS number: 12125-02-9
Ammonium chloride ((NH4)Cl); ammonium muriate; sal ammoniac; salmiac.
ClH4N; mol wt 53.49.
Cl 66.28%, H 7.54%, N 26.19%.
NH4Cl.

Description and references

Contains 99.5-99.8% NH4Cl; principal impurity is NaCl; exists in two temperature dependent crystal modifications. Prepn and properties: Gmelins, Ammonium (8th ed.) 23, pp 150-184 (1936); N. C. R. Kane, “Ammonium Chloride” in Mellor's Vol. VIII, supplement 1, Nitrogen (part 1), 378-432 (1964). Manuf: A. W. Bamforth, S. R. S. Sastry, Chem. Process Eng. 53, 72 (1972). NMR study: K. H. Michel, Proc. Int. Sch. Phys. 1976, 392. Toxicity data: E. M. Boyd, K. G. W. Seymour, Exp. Med. Surg. 4, 223 (1946). Brief review: C. W. Weston in Kirk-Othmer Encyclopedia of Chemical Technology vol 2 (Wiley-Interscience, New York, 4th ed., 1992) pp 695-698. Review of properties and use in water treatment: P. Smeets, Trib. Eau 570, 26-29 (1994).

Properties

Colorless, odorless crystals or cryst masses; or white, granular powder; cooling, saline taste; somewhat hygroscopic. Tendency to cake. Strongly endothermic. d204 1.5274. Sublimes without melting. Soly in water (w/w): 22.9% (0°); 26.0% (15°); 28.3% (25°); 39.6% (80°). Freely sol in water, glycerin, more so in boiling water. HCl and NaCl decrease soly in water. Sparingly sol in alcohol. Almost insol in acetone, ether, ethyl acetate. pH of aq solns (25°): 1% 5.5; 3% 5.1; 10% 5.0. LD50 in rats (mg/kg): 30 i.m. (Boyd, Seymour). LD50 in rats (mg/kg): 1650 orally (Smeets).

Caution

Potential symptoms of overexposure to fumes are irritation of eyes, skin, respiratory system; cough, dyspnea, pulmonary sensitization. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 16.

Use

As a flux in zinc and tin plating; electroplating, electrolytic refining of zinc; etching solutions in manufacture of printed circuit boards; in dry and Leclanché batteries; as a nitrogen source for fertilization of rice and wheat, manufacturing of explosives; flame suppressant; hardener for formaldehyde-based adhesives; mordant for dyes and printing.

Therapeutic Category

Acidifier.

Therapeutic Category (Veterinary)

Expectorant; diaphoretic; acidifying diuretic.

Keywords

Acidifier