Barium cyanide

Barium cyanide is a chemical compound with the formula Ba(CN)₂. It is synthesized by the reaction of hydrogen cyanide and barium hydroxide in water or petroleum ether.^[1] It is a white crystalline salt.

Barium cyanide

Names
IUPAC name Barium dicyanide
Identifiers
CAS Number	542-62-1 Y
3D model (JSmol)	Interactive image
ChemSpider	10496
ECHA InfoCard	100.008.021
EC Number	208-882-3
PubChem CID	10961
UNII	62X6NA0R43 Y
CompTox Dashboard (EPA)	DTXSID3023895
InChI InChI=1S/2CN.Ba/c2*1-2;/q2*-1;+2 Key: UNLSXXHOHZUADN-UHFFFAOYSA-N InChI=1/2CN.Ba/c2*1-2;/q2*-1;+2 Key: UNLSXXHOHZUADN-UHFFFAOYAI
SMILES [Ba+2].[C-]#N.[C-]#N
Properties
Chemical formula	Ba(CN)2
Molar mass	189.362 g/mol
Appearance	white crystalline powder
Melting point	600 °C (1,112 °F; 873 K)
Solubility in water	80 g/100 mL (14 °C)
Solubility	Soluble in ethanol
Vapor pressure	740 mmHg
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H300, H310, H330, H410
Precautionary statements	P260, P262, P264, P270, P271, P273, P280, P284, P301+P316, P302+P352, P304+P340, P316, P320, P321, P330, P361+P364, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)	3 0 0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Uses

Barium cyanide is used in electroplating and other metallurgical processes.

Preparation

Barium cyanide is prepared by reacting barium hydroxide with hydrocyanic acid:

Ba(OH)₂ + 2HCN → Ba(CN)₂ +2H₂O

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.^[2]

When barium cyanide is heated to 300°C with steam present, the nitrogen evolves to ammonia, leaving barium formate.^{[citation needed]}

Ba(CN)₂ + 4 H₂O = Ba(HCOO)₂ + 2 NH₃

Aqueous solutions of barium cyanide dissolve insoluble cyanides of some of the heavy metals forming crystalline double salts. For example, BaHg(CN)₄.3H₂O in needles, 2Ba(CN)₂.3Hg(CN)₂.23H₂O in transparent octahedra, and Ba(CN)₂.Hg(CN)₂.HgI₂.6H₂O.^[3]