Silver cyanide is the chemical compound with the formula AgCN. It is a white salt that is precipitated upon treatment of solutions containing Ag+ with cyanide, which is used in some schemes to recover silver from solution. Silver cyanide is used in silver-plating.
The structure of silver cyanide consists of -[Ag-CN]- chains in which the linear two-coordinate Ag+ ions are bridged by the cyanide ions,[3] typical of silver(I) and other d10 ions. This is the same binding mode as seen in the more famous case of Prussian blue. These chains then pack hexagonally with adjacent chains offset by +/- 1/3 of the c lattice parameter. This is the same as the structure adopted by the high temperature polymorph of copper(I) cyanide. The silver to carbon and silver to nitrogen bond lengths in AgCN are both ~2.06 Å[4] and the cyanide groups show head-to-tail disorder.[5]
ReactionsEdit
AgCN precipitates upon the addition of sodium cyanide to a solution containing Ag+. On the addition of further cyanide, the precipitate dissolves to form linear [Ag(CN)2]−(aq) and [Ag(CN)3]2−(aq). Silver cyanide is also soluble in solutions containing other ligands such as ammonia or tertiary phosphines.
Silver cyanides form structurally complex materials upon reaction with other anions.[6] Some silver cyanides are luminescent.[7]
UsesEdit
"Cyanidation" is widely used in the isolation of silver from its ores. Partial purification of silver compounds is usually effected by froth flotation. The silver ion is then separated from the skimmed froth with cyanide, yielding a solution of [Ag(CN)2]−. The silver metal can then be plated out by electrolysis of such solutions.[8]
Both AgCN and KAg(CN)2 have been used in silver-plating solutions since at least 1840 when the Elkington brothers patented their recipe for a silver-plating solution. A typical, traditional silver-plating solution would contain 15-40 g·L−1 KAg(CN)2 , 12-120 g·L−1 KCN and 15 g·L−1 K2CO3.[9]
^John Rumble (June 18, 2018). CRC Handbook of Chemistry and Physics (99 ed.). CRC Press. pp. 5–189. ISBN978-1138561632.
^ abZumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A23. ISBN978-0-618-94690-7.
^Bowmaker, Graham A.; Kennedy, Brendan J.; Reid, Jason C. (1998). "Crystal Structures of AuCN and AgCN and Vibrational Spectroscopic Studies of AuCN, AgCN, and CuCN". Inorg. Chem.37 (16): 3968–3974. doi:10.1021/ic9714697. PMID 11670511.
^Hibble, S. J.; Cheyne, S. M.; Hannon, A. C.; Eversfield, S. G. (2002). "Beyond Bragg scattering: the structure of AgCN determined from total neutron diffraction". Inorganic Chemistry. 41 (5): 1042–1044. doi:10.1021/ic015610u. PMID 11874335.
^Bryce, David L.; Wasylishen, Roderick E. (2002). "Insight into the Structure of Silver Cyanide from 13C and 15N Solid-State NMR Spectroscopy". Inorganic Chemistry. 41 (16): 4131–4138. doi:10.1021/ic0201553. ISSN 0020-1669. PMID 12160400.
^Urban, Victoria; Pretsch, Thorsten; Hartl, Hans (2005-04-29). "From AgCN Chains to a Fivefold Helix and a Fishnet-Shaped Framework Structure". Angewandte Chemie International Edition. 44 (18): 2794–2797. doi:10.1002/anie.200462793. ISSN 1433-7851. PMID 15830404.
^Omary, Mohammad A.; Webb, Thomas R.; Assefa, Zerihun; Shankle, George E.; Patterson, Howard H. (1998). "Crystal Structure, Electronic Structure, and Temperature-Dependent Raman Spectra of Tl[Ag(CN)2]: Evidence for Ligand-Unsupported Argentophilic Interactions". Inorganic Chemistry. 37 (6): 1380–1386. doi:10.1021/ic970694l. ISSN 0020-1669. PMID 11670349.
^Etris, S. F. (2010). "Silver and Silver Alloys". Kirk-Othmer Encyclopedia of Chemical Technology. pp. 1–43. doi:10.1002/0471238961.1909122205201809.a01.pub3. ISBN978-0471238966.
^Blair, Alan (2000). "Silver plating". Metal Finishing. 98 (1): 298–303. doi:10.1016/S0026-0576(00)80339-6.
October 25, 2023
silver, cyanide, chemical, compound, with, formula, agcn, white, salt, that, precipitated, upon, treatment, solutions, containing, with, cyanide, which, used, some, schemes, recover, silver, from, solution, used, silver, plating, nnamesiupac, name, other, name. Silver cyanide is the chemical compound with the formula AgCN It is a white salt that is precipitated upon treatment of solutions containing Ag with cyanide which is used in some schemes to recover silver from solution Silver cyanide is used in silver plating Silver cyanide Ag C NNamesIUPAC name Silver cyanideOther names Argentous cyanideIdentifiersCAS Number 506 64 9 Y3D model JSmol Interactive imageChemSpider 10043 YECHA InfoCard 100 007 317EC Number 208 048 6PubChem CID 10475RTECS number VW3850000UNII 33RV6XQ01M YUN number 1684CompTox Dashboard EPA DTXSID9024306InChI InChI 1S CN Ag c1 2 q 1 1 YKey LFAGQMCIGQNPJG UHFFFAOYSA N YInChI 1 CN Ag c1 2 q 1 1Key LFAGQMCIGQNPJG UHFFFAOYAMSMILES C N Ag PropertiesChemical formula AgCNMolar mass 133 8856 g molAppearance colorless gray impure crystalsOdor odorlessDensity 3 943 g cm3Melting point 335 C 635 F 608 K decomposes Solubility in water 0 000023 g 100 mL 20 C Solubility product Ksp 5 97 10 17 1 Solubility soluble in concentrated ammonia boiling nitric acid ammonium hydroxide KCN insoluble in alcohol dilute acidMagnetic susceptibility x 43 2 10 6 cm3 molRefractive index nD 1 685StructureCrystal structure hexagonalCoordination geometry linearThermochemistryStd molarentropy S 298 84 J mol 1 K 1 2 Std enthalpy offormation DfH 298 146 kJ mol 1 2 HazardsOccupational safety and health OHS OSH Main hazards toxicGHS labelling PictogramsSignal word DangerHazard statements H290 H300 H310 H315 H318 H330 H410Precautionary statements P234 P260 P262 P264 P270 P271 P273 P280 P284 P301 P310 P302 P350 P302 P352 P304 P340 P305 P351 P338 P310 P320 P321 P322 P330 P332 P313 P361 P362 P363 P390 P391 P403 P233 P404 P405 P501NFPA 704 fire diamond 311Flash point 320 C 608 F 593 K Lethal dose or concentration LD LC LD50 median dose 123 mg kg oral rat Related compoundsOther anions AgClOther cations NaCN Copper I cyanideExcept where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa N verify what is Y N Infobox references Contents 1 Structure 2 Reactions 3 Uses 4 See also 5 ReferencesStructure EditThe structure of silver cyanide consists of Ag CN chains in which the linear two coordinate Ag ions are bridged by the cyanide ions 3 typical of silver I and other d10 ions This is the same binding mode as seen in the more famous case of Prussian blue These chains then pack hexagonally with adjacent chains offset by 1 3 of the c lattice parameter This is the same as the structure adopted by the high temperature polymorph of copper I cyanide The silver to carbon and silver to nitrogen bond lengths in AgCN are both 2 06 A 4 and the cyanide groups show head to tail disorder 5 Reactions EditAgCN precipitates upon the addition of sodium cyanide to a solution containing Ag On the addition of further cyanide the precipitate dissolves to form linear Ag CN 2 aq and Ag CN 3 2 aq Silver cyanide is also soluble in solutions containing other ligands such as ammonia or tertiary phosphines Silver cyanides form structurally complex materials upon reaction with other anions 6 Some silver cyanides are luminescent 7 Uses Edit Cyanidation is widely used in the isolation of silver from its ores Partial purification of silver compounds is usually effected by froth flotation The silver ion is then separated from the skimmed froth with cyanide yielding a solution of Ag CN 2 The silver metal can then be plated out by electrolysis of such solutions 8 Both AgCN and KAg CN 2 have been used in silver plating solutions since at least 1840 when the Elkington brothers patented their recipe for a silver plating solution A typical traditional silver plating solution would contain 15 40 g L 1 KAg CN 2 12 120 g L 1 KCN and 15 g L 1 K2CO3 9 See also EditList of compounds with carbon number 1References Edit John Rumble June 18 2018 CRC Handbook of Chemistry and Physics 99 ed CRC Press pp 5 189 ISBN 978 1138561632 a b Zumdahl Steven S 2009 Chemical Principles 6th Ed Houghton Mifflin Company p A23 ISBN 978 0 618 94690 7 Bowmaker Graham A Kennedy Brendan J Reid Jason C 1998 Crystal Structures of AuCN and AgCN and Vibrational Spectroscopic Studies of AuCN AgCN and CuCN Inorg Chem 37 16 3968 3974 doi 10 1021 ic9714697 PMID 11670511 Hibble S J Cheyne S M Hannon A C Eversfield S G 2002 Beyond Bragg scattering the structure of AgCN determined from total neutron diffraction Inorganic Chemistry 41 5 1042 1044 doi 10 1021 ic015610u PMID 11874335 Bryce David L Wasylishen Roderick E 2002 Insight into the Structure of Silver Cyanide from 13C and 15N Solid State NMR Spectroscopy Inorganic Chemistry 41 16 4131 4138 doi 10 1021 ic0201553 ISSN 0020 1669 PMID 12160400 Urban Victoria Pretsch Thorsten Hartl Hans 2005 04 29 From AgCN Chains to a Fivefold Helix and a Fishnet Shaped Framework Structure Angewandte Chemie International Edition 44 18 2794 2797 doi 10 1002 anie 200462793 ISSN 1433 7851 PMID 15830404 Omary Mohammad A Webb Thomas R Assefa Zerihun Shankle George E Patterson Howard H 1998 Crystal Structure Electronic Structure and Temperature Dependent Raman Spectra of Tl Ag CN 2 Evidence for Ligand Unsupported Argentophilic Interactions Inorganic Chemistry 37 6 1380 1386 doi 10 1021 ic970694l ISSN 0020 1669 PMID 11670349 Etris S F 2010 Silver and Silver Alloys Kirk Othmer Encyclopedia of Chemical Technology pp 1 43 doi 10 1002 0471238961 1909122205201809 a01 pub3 ISBN 978 0471238966 Blair Alan 2000 Silver plating Metal Finishing 98 1 298 303 doi 10 1016 S0026 0576 00 80339 6 Retrieved from https en wikipedia org w index php title Silver cyanide amp oldid 1176824404, wikipedia, wiki, book, books, library,
