Ammonia - Introduction

Ammonia is a chemical compound with the formula NH₃. At 20° Celsius and 1 atm pressure, ammonia is a gas with a characteristic pungent smell. Its main uses are in the production of fertilizers, explosives and polymers. Ammonia can also be used directly as a fertilizer by forming a solution with irrigation water, without additional chemical processing. This later use allows the continuous growing of nitrogen dependent crops such as Maize without crop rotation (however, leading to poor soils).

Ammonia is very well suited as a refrigerant, since it liquefies readily under pressure, and was used in virtually all refrigeration units prior to the advent of freons. Since the implication of freons as major greenhouse gases and as killer of the ozone layer, ammonia is again seeing increasing use as a refrigerant.

Ammonia is found in small quantities as ammonium carbonate in the atmosphere, being produced from the putrefaction of nitrogenous animal and vegetable matter. Ammonium salts are also found in small quantities in rain-water, whilst ammonium chloride (sal-ammoniac) and ammonium sulfate are found in volcanic districts; and crystals of ammonium bicarbonate have been found in Patagonian guano. Ammonium salts also are found in fertile soils, in sea-water, and in most plant and animal liquids, and also in urine.