Ammonium cyanide

Structural formula
General
Surname	Ammonium cyanide
Molecular formula	NH 4 CN
Brief description	colorless solid with a smell of ammonia
External identifiers / databases
PubChem	159440
Wikidata	Q420692
properties
Molar mass	44.06 g mol −1
Physical state	firmly
density	1.02 g cm −3
solubility	very easily soluble in water
safety instructions
H and P phrases	H: 330-310-300-410
	EUH: 032
	P: ?
Thermodynamic properties
ΔH f 0	0.4 kJ / mol
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Ammonium cyanide is a chemical compound from the group of cyanides . It is the ammonium salt of hydrocyanic acid . In its pure form it forms colorless, cube-shaped crystals which, due to slow decomposition, smell of ammonia and hydrogen cyanide at the same time .

Extraction and presentation

Ammonium cyanide can be produced by dry heating ammonium hexacyanidoferrate (II) , (NH ₄ ) ₄ [Fe (CN) ₆ ] · 3 H ₂ O or a mixture of potassium cyanide and ammonium chloride. When heated gently in a water bath, the mixture melts and develops vaporous ammonium cyanide, which can be condensed with an ice-common salt mixture :

${\ displaystyle \ mathrm {KCN + NH_ {4} Cl \ longrightarrow NH_ {4} CN + KCl}}$

Furthermore, it is formed when dry ammonia is passed over glowing coals in a porcelain bowl and the cyanide is collected in a cooled receiver.

properties

Ammonium cyanide can be kept undecomposed when refrigerated, while it decomposes noticeably in the air at normal temperature. The steam can be ignited, it burns with a yellowish flame to form ammonium carbonate . The aqueous solution of ammonium cyanide has an alkaline reaction . It is slightly more soluble in ethanol than in water. Ammonium cyanide reacts with bromine and chlorine to generate heat, while potassium permanganate oxidizes it directly to urea . Ammonium cyanide is similar toxic as cyanide .

Ammonium cyanide crystallizes in the tetragonal crystal system with the space group P 4 ₂ / mcm (space group no. 132) . Template: room group / 132

safety instructions

All water-soluble cyanides are poisonous, whereby they cause asphyxiation by blocking the enzyme cytochrome c oxidase in the respiratory chain . When working with the substance, protective gloves , a dust mask and gas filter B breathing protection must be used. Furthermore, whenever hydrogen cyanide has to be expected, it is essential to work in the fume cupboard.

storage

Ammonium cyanide should be stored in a cool place with the strict exclusion of oxygen and moisture.

literature

Brockhaus ABC . Volume 1 A – K, VEB FA Brockhaus Verlag, Leipzig 1965.

Individual evidence

↑ ^a ^b ^c ^d ^e Roger Blachnik (Ed.): Paperback for chemists and physicists . Volume III: Elements, Inorganic Compounds and Materials, Minerals . founded by Jean d'Ans, Ellen Lax. 4th, revised and revised edition. Springer, Berlin 1998, ISBN 3-540-60035-3 , pp. 586 ( limited preview in Google Book search).
^ Entry on prussic acid salts in the GESTIS substance database of the IFA , accessed on February 1, 2016 (JavaScript required)
↑ Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the indicated labeling it falls under the group entry salts of hydrogen cyanide with the exception of complex cyanides such as ferrocyanides, ferricyanides and mercuric oxycyanide and those specified elsewhere in this Annex in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-20.

[Jean_Ans,_Ellen_Lax-1] Roger Blachnik (Ed.): Paperback for chemists and physicists . Volume III: Elements, Inorganic Compounds and Materials, Minerals . founded by Jean d'Ans, Ellen Lax. 4th, revised and revised edition. Springer, Berlin 1998, ISBN 3-540-60035-3 , pp. 586 ( limited preview in Google Book search).

[GESTIS-2] Entry on prussic acid salts in the GESTIS substance database of the IFA , accessed on February 1, 2016 (JavaScript required)

[CLP_100.240.759-3] Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the indicated labeling it falls under the group entry salts of hydrogen cyanide with the exception of complex cyanides such as ferrocyanides, ferricyanides and mercuric oxycyanide and those specified elsewhere in this Annex in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[CRC90_5_20-4] David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-20.