Ammonium chloride (NH₄Cl) is an inorganic salt, composed of the ammonium cation (NH₄⁺) and the chloride anion (Cl-). It occurs as a water-soluble crystalline solid and it is used in various fields, including the chemical industry and the laboratory research. This compound can be formed by the reaction between ammonia (NH₃) and hydrochloric acid (HCl).