n.
Colourless, pungent gas composed of nitrogen and hydrogen , chemical formula NH 3 .
Easily liquefied by compression or cooling for use in refrigerating and air-conditioning equipment, it is manufactured in huge quantities. Ammonia is made by the Haber-Bosch process (see Fritz Haber ). Its major use is as a fertilizer , applied directly to soil from tanks of the liquefied gas. Also employed as fertilizers are salt s of ammonia, including ammonium phosphate and ammonium nitrate (the latter used in high explosives as well). Ammonia has many other industrial uses as a raw material, catalyst , and alkali . It dissolves readily in water to form ammonium hydroxide, an alkaline solution (see base ) familiar as a household cleaner.