Definition and Usage :
The chemical compound silver cyanide, with the formula AgCN. This white solid is formed by treating solutions containing Ag+ with cyanide. This precipitation step is used in some schemes to recover silver from solution. Silver cyanide is used in silver plating.
Its structure consists of -[Ag-CN] chains in which linear two-coordinated Ag+ ions, specific to silver(I) and other d10 ions, are bridged by cyanide ions. (The same bonding mode seen in the more famous example of Prussian blue.) These chains are then hexagonally packed with adjacent chains with +/- 1/3 of the "c" lattice parameter. This is the same structure adopted by the high-temperature polymorph of copper(I) cyanide. The silver-carbon and silver-nitrogen bond lengths in AgCN are both ~2.09 Å, and the cyanide groups exhibit head-to-tail disorder.
Silver cyanide is the general name for hydrocyanic acid and metal salts derived from this acid. All are highly toxic. The most important are sodium cyanide and potassium cyanide. They are obtained by passing a mixture of ammonia (NH3) and CO gases over heated dry carbons in industry. HCN (Hydrocyanic acid) is a very volatile liquid with the smell of bitter almonds. It boils at 28 degrees Celsius. Its solution in water is a very weak acid. Cyanide and its compounds can be produced by chemical means, as well as by some plants and animals. There are many plants, bacteria and insects that produce cyanide naturally. Cherries, almonds, apricots, peaches, plums, beans, potatoes, radishes, cabbage, turnips, broccoli and corn naturally produce cyanide compounds.