Little data is available at very high temperatures and pressures, such as supercritical conditions. Gaseous ammonia turns to the colourless liquid which boils at −33.1 ☌ (−27.58 ☏), and freezes to colourless crystals at −77.7 ☌ (−107.86 ☏). It is easily liquefied due to the strong hydrogen bonding between molecules. It is lighter than air, its density being 0.589 times that of air. Substances containing ammonia, or those that are similar to it, are called ammoniacal.Īmmonia is a colourless gas with a characteristically pungent smell.
Īmmonia is also found throughout the Solar System on Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto, among other places: on smaller, icy bodies such as Pluto, ammonia can act as a geologically important antifreeze, as a mixture of water and ammonia can have a melting point as low as −100 ☌ (−148 ☏ 173 K) if the ammonia concentration is high enough and thus allow such bodies to retain internal oceans and active geology at a far lower temperature than would be possible with water alone. Crystals of ammonium bicarbonate have been found in Patagonia guano. Ammonia and ammonium salts are also found in small quantities in rainwater, whereas ammonium chloride ( sal ammoniac), and ammonium sulfate are found in volcanic districts. Natural occurrence Īmmonia is a chemical found in trace quantities on Earth, being produced from nitrogenous animal and vegetable matter. Joseph Priestley noticed that when this salt reacted with lime, a vapor was released, which he termed as Ammonia. This white crystalline salt was called "salt of Ammon" ( sal ammoniac). Roman visitors to oracle temple of Amun in Siwa oasis collected a white crystalline material from the ceiling and walls caused by various pollutants. In any case, that salt ultimately gave ammonia and ammonium compounds their name. According to Herbert Hoover's commentary in his English translation of Georgius Agricola's De re metallica, it is likely to have been common sea salt. However, the description Pliny gives of the salt does not conform to the properties of ammonium chloride. Pliny, in Book XXXI of his Natural History, refers to a salt named hammoniacum, so called because of its proximity to the nearby Temple of Jupiter Amun ( Greek Ἄμμων Ammon) in the Roman province of Cyrenaica. The concentration of such solutions is measured in units of the Baumé scale ( density), with 26 degrees Baumé (about 30% of ammonia by weight at 15.5 ☌ or 59.9 ☏) being the typical high-concentration commercial product. Household ammonia or ammonium hydroxide is a solution of NH 3 in water. NH 3 boils at −33.34 ☌ (−28.012 ☏) at a pressure of one atmosphere, so the liquid must be stored under pressure or at low temperature. The Haber process that enabled industrial production was invented at the beginning of the 20th century, revolutionizing agriculture. įor fundamental reasons, the production of ammonia from the elements hydrogen and nitrogen is difficult, requiring high pressures and high temperatures. Industrial ammonia is sold either as ammonia liquor (usually 28% ammonia in water) or as pressurized or refrigerated anhydrous liquid ammonia transported in tank cars or cylinders.
The global industrial production of ammonia in 2021 was 235 million tonnes. In many countries it is classified as an extremely hazardous substance, and is subject to strict reporting requirements by facilities that produce, store, or use it in significant quantities. It is mainly collected by downward displacement of both air and water.Īlthough common in nature-both terrestrially and in the outer planets of the Solar System-and in wide use, ammonia is both caustic and hazardous in its concentrated form.
Ammonia in pure form is also applied directly into the soil.Īmmonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceutical products and is used in many commercial cleaning products.
Around 70% of ammonia is used to make fertilisers in various forms and composition, such as urea and diammonium phosphate. Biologically, it is a common nitrogenous waste, particularly among aquatic organisms, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to 45% of the world's food and fertilizers. A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Ammonia is an inorganic compound of nitrogen and hydrogen with the formula N H 3.
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