Ammonium chloride and water react to yield ammonium hydroxide and hydrochloric acid. Ammonium chloride is called an acid salt, as it is the combination of strong acid and a weak base. The hydrolysis of an acidic salt, such as ammonium chloride, is an endothermic reaction.
Ammonium chloride is an acid-forming salt that forms a white or colorless crystalline powder. It is hygroscopic in nature, so absorbs water from the atmosphere, and has a saline taste. When ammonium chloride salt is dissolved in water, the solution temperature reduces as heat is absorbed by the reaction that takes place. Hence, the reaction is an endothermic one. The pH of a solution formed this way is below 7 -- that is, the solution is acidic.