Ammonium chloride (chemical formula: NH4Cl) is colorless cubic crystal or white crystal. It tastes salty, cool and slightly bitter. It is easily soluble in water and liquid ammonia and slightly soluble in alcohol, but insoluble in acetone and ether. The aqueous solution is weakly acidic and the acidity increases when heated. Due to the coordination of ammonium ions, the ammonium chloride solution is corrosive to metals, especially copper.