Barium cyanide is a
chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
with the formula Ba(CN)
2. It is synthesized by the reaction of
hydrogen cyanide
Hydrogen cyanide (formerly known as prussic acid) is a chemical compound with the chemical formula, formula HCN and structural formula . It is a highly toxic and flammable liquid that boiling, boils slightly above room temperature, at . HCN is ...
and
barium hydroxide in water or
petroleum ether
Petroleum ether is the petroleum fraction consisting of aliphatic hydrocarbons and boiling in the range 35–60 °C, and commonly used as a laboratory solvent. Despite the name, petroleum ether is not an ether; the term is used only figurativ ...
. It is a white crystalline salt.
Uses
Barium cyanide is used in
electroplating
Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the redox, reduction of cations of that metal by means of a direct current, direct electric cur ...
and other metallurgical processes.
Preparation
Barium cyanide is prepared by reacting
barium hydroxide with
hydrocyanic acid:
:Ba(OH)
2 + 2HCN → Ba(CN)
2 +2H
2O
The product is crystallized from the solution.
Reactions
Barium cyanide reacts with water and carbon dioxide in air slowly, producing highly toxic hydrogen cyanide gas.
When barium cyanide is heated to 300°C with steam present, the nitrogen evolves to ammonia, leaving barium formate.
:Ba(CN)
2 + 4 H
2O = Ba(HCOO)
2 + 2 NH
3
Aqueous solutions of barium cyanide dissolve insoluble cyanides of some of the heavy metals forming crystalline double salts. For example, BaHg(CN)
4.3H
2O in needles, 2Ba(CN)
2.3Hg(CN)
2.23H
2O in transparent octahedra, and Ba(CN)
2.Hg(CN)
2.HgI
2.6H
2O.
References
Barium compounds
Cyanides
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