9. What is ammonium chloride?

Ammonium chloride (abbreviated as Ammonium Chloride) is an inorganic compound with the chemical formula NH4Cl, serving as the ammonium salt of hydrochloric acid and primarily produced as a byproduct in the soda ash industry. This substance exists as small white or yellowish square or octahedral crystals, available in both powder and granular forms. While granular Ammonium Chloride is less hygroscopic and easier to store, the powdered form is predominantly used as the base material for manufacturing compound fertilizers.
Ammonium chloride is highly soluble in water and glycerol, slightly soluble in ethanol, and insoluble in benzene or ether. It readily loses its water of crystallization in dry air and becomes corrosive due to hydrolysis in humid environments, producing hydrogen chloride. While ammonium salts generally exhibit alkaline properties, ammonium chloride itself is an acidic substance. When heated, it decomposes and reacts with acids to form ammonium salts. During intense combustion, it generates highly irritating gases such as nitrogen oxides and ammonia. In galvanizing processes, it is typically mixed with zinc chloride.