Thursday, January 23, 2014

Silver nitrate

Silver nitrate is an inorganic compound with chemical formula AgNO₃. This compound is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides. It was once called lunar caustic because silver was called luna by the ancient alchemists, who believed that silver was associated with the moon.
In solid silver nitrate, the silver ions are three-coordinated in a trigonal planar arrangement


Silver nitrate can be prepared by reacting silver, such as a silver bullion or silver foil, with nitric acid, resulting in silver nitrate, water, and oxides of nitrogen. Reaction byproducts depend upon the concentration of nitric acid used.

3 Ag + 4 HNO
3
(cold and diluted) → 3 AgNO
3
 + 2 H
2
O
NO
Ag + 2 HNO
3
(hot and concentrated) → AgNO
3
 + H
2
O
 + NO
2
This is performed under a fume hood because of toxic nitrogen oxide(s) evolved during the reaction.