Page 12 - Curriculum Visions Dynamic Book

Ammonia
Ammonia, whose formula is NH3, is a compound of nitrogen and hydrogen.
The word may come from an association with the ancient Egyptian god Ammon. In former times ammonia was obtained
by boiling animal horns and hoofs.
Ammonia is a colourless gas. It is not actually poisonous, but inhaling its fumes can cause people to stop breathing, so it can have very serious effects.
Ammonia can always be detected by
its irritating smell. It is famous for its use
as “smelling salts” in the last century, in which a compound of ammonia, ammonium carbonate, was used. Smelling salts were used to revive women who had swooned (not actually fainted, but who were putting on a show as a social gesture that they had been offended). It was very difficult to continue
to pretend to have fainted when the smell
of ammonia was irritating the throat, and so they “revived”.
Ammonia is extremely soluble in water, where it produces an alkaline liquid, ammonium hydroxide. This dilute solution is commonly sold for use in household disinfectants and cleaning under the title household ammonia.
Ammonia is also one of the most important starting materials for making artificial fertilisers.
 Ammonia can be added to irrigation water and applied to fields at the same time as they are watered. In such diluted amounts its smell cannot be detected.
Nitrogen
 A representation of an ammonia molecule.
Ammonia for refrigeration
Ammonia gas has a high boiling point (about -33°C). It also absorbs a large amount of heat energy
as it vaporises. It is not corrosive and is easy to obtain. This makes
it particularly suitable for use in refrigeration systems, which work by boiling and then liquifying a material as it passes through the refrigeration pipework.
Hydrogen
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