Silver cyanide AgCN

Silver Cyanide. Silver cyanide, AgCN, forms as a precipitate when stoichiometric quantities of silver nitrate and a soluble cyanide are mixed. Sdver(I) ion readily forms soluble complexes, ie, Ag(CN) 2 01 Ag(CN) 2> die presence of excess cyanide ion. 

Cyanide Complexes. Insoluble silver cyanide, AgCN, is readily dissolved in an excess of alkah cyanide. The predominant silver species present in such solutions is Ag(CN) 2) with some Ag(CN) 3 and Ag(CN) 4. Virtually all silver salts, including the insoluble silver sulfide, dissolve in the presence of excess cyanide because the dissociation constant for the Ag(CN) 2 complex is only 4 x 10 (see Cyanides). 

Silver Cyanide, AgCN, wh odorless tasteless powd, mp 320° (dec), d 3-95, highly toxic (Ref 3, p 1104)... 

Silver nitrate solution white precipitate of silver cyanide, AgCN, readily soluble in excess of the cyanide solution forming the complex ion, dicyano-argentate(I) [Ag(CN)2] (cf. Section III.6, reaction 7) ... 

In the electroplating of a silver spoon, the spoon acts as the cathode and a piece of pure silver as the anode. Both dip into a solution of silver cyanide (AgCN). Suppose that a current of 1.5 A is passed through such a cell for 22 minutes and that the spoon has a surface area of 16 cm. Calculate the average thickness of the silver layer deposited on the spoon, taking the density of silver to be 10.5 g cm . ... 

Representative Chemicals Silver chloride (AgCl) Silver nitrate (AgNOs) Silver cyanide (AgCN)... 

Silver cyanide, AgCN 2.2X10 SrC204-H20 5.6X10 ... 

The solubility of the complex anion Ag(CN)2 in contrast to the high insolubility of neutral silver cyanide (AgCN) was exploited for the determination of silver (and/or cyanide) by Justus von Liebig as long ago as 1851 this procedure may well be cited as the best established complexometric titration preceding the great developments brought about by G. Schwarzenbach in 1940 when he pioneered the use of ethylenediaminetetraacetic acid, EDTA, and other aminopolycarboxylic acids as titrants" and opened up new vistas in titrimetry (see Section 10.6). 

There are exceptions to this rule, however, particularly when the electrons on the carbon of cyanide are tied up in a covalent bond. Both silver cyanide (AgCN) and cuprous cyanide (CuCN) have bonds between the metal and carbon (Ag-C or Cu-C) that have significant covalent character. The Ag and Cu ions are not charge dense, and they prefer to coordinate to atoms that are also not dense in charge (the C end of cyanide). If the metal-carbon bond in M-CN is covalent, the electrons on carbon are shared and less available for donation, which makes carbon less nucleophilic. In both AgCN and CuCN, the nitrogen atom is more nucleophilic and reaction with an alkyl halide R-X leads to a molecule called an isocyanide (or isonitrile, R-+N=C ). Isocyanides and the reaction of such compounds are not discussed in this hook. 

Mercury (I) cyanide, Hg2(CN)2 Silver cyanide, AgCN Halides Fluorides... 

Cyanides such as silver cyanide AgCN, copper cyanide Cu(CN)2, and gold cyanide AuCN, that are used in galvanoplastic processes, lead to pitting corrosion of aluminium due to the presence of cations of heavy metals (silver, copper, and gold). 

An electrochemical cell is constructed for the purpose of determining the of silver cyanide (AgCN) at 25°C. One half-cell consists of a silver electrode in a 1.00 Af solution of silver nitrate. The other half-cell consists of a silver electrode in a saturated solution of silver cyanide. The cell potential is measured and found to be 0.470 V. Determine the concentration of silver ion in the saturated silver cyanide solution and the value of ATsp for AgCN. 

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