Ammonium chloride (abbreviated as ammonium chlorate or NH4Cl) is an inorganic compound, which is the ammonium salt of hydrochloric acid and is mostly a by-product of the soda ash industry. Ammonium chloride appears as white or slightly yellowish small crystals with a square or octahedral shape, available in both powdered and granular forms. Granular ammonium chloride is not easily hygroscopic and is easy to store, while powdered ammonium chloride is more commonly used as a basic fertilizer for producing compound fertilizers.
Ammonium chloride is easily soluble in water and glycerin, slightly soluble in ethanol, and insoluble in benzene and ether. It is prone to efflorescence and loss of crystal water in dry air, and undergoes hydrochloric acid corrosion due to hydrolysis in humid air. All ammonium salts possess the common properties of bases, but ammonium chloride itself is an acidic substance. It is easily decomposed when heated and reacts with acids to produce ammonium salts. Upon intense burning, it can generate nitrogen oxides, ammonia, and other strongly irritating gases. In the hot-dip galvanizing process, it is generally used in mixture with zinc chloride.
