Zinc-Potassium cyanide

Potassium zinc cyanide, zinc potassium cyanide. 

Zinc potassium cyanide c/5 -Ethylene from acetylene derivs. 

Cyanide Copper cyanide Nickel cyanide Potassium cyanide Silver cyanide Sodium cyanide Zinc cyanide... 

H.A. Arida and R.F. Aglan, A solid-state potassium selective electrode based on potassium zinc ferro-cyanide ion exchanger. Anal. Lett. 36, 895-907 (2003). 

Muzzarelli and Sipos [622] showed that a column of chitosan (15 x 10 mm) can be used to concentrate zinc from 3 litres of seawater before determination by anodic-stripping voltammetry with a composite mercury-graphite electrode. Zinc (and lead) are eluted from the column by 2 M ammonium acetate (50 ml), copper by 0.01 M EDTA (10 ml), and cadmium by 0.1 M potassium cyanide (3 ml). 

Cyanide occurs most commonly as hydrogen cyanide in water, although it can also occur as the cyanide ion, alkali and alkaline earth metal cyanides (potassium cyanide, sodium cyanide, calcium cyanide), relatively stable metallocyanide complexes (ferricyanide complex [Fe(CN)6]-3), moderately stable metallocyanide complexes (complex nickel and copper cyanide), or easily decomposable metallocyanide complexes (zinc cyanide [Zn(CN)2], cadmium cyanide [Cd(CN)2]). Hydrogen cyanide and cyanide ion combined are commonly termed free cyanide. The environmental fate of these cyanide compounds varies widely (Callahan et al. 1979). 

Potassium cyanide Potassium fluoride Unknown Unknown s s Zinc chloride Unknown s... 

Zinc cyanide is precipitated by mixing solutions of potassium cyanide and a soluble zinc salt, such as zinc chloride or sulfate ... 

Electrodeposition on Zn Electrodes Rezaite and Vishomirskis [209, 210] have investigated the effect of potassium cyanide on the electrodeposition of zinc from zincate solutions on the Zn electrode. It is known that cyanide added to the zincate solution led to high-quality zinc coatings. The presence of KCN decreased the limiting current of Zn(II). 

Reich and Richter found that it is easier to isolate it from the zinc than from the original blende. They reduced indium oxide in a current of hydrogen or illuminating gas and melted the metal under potassium cyanide (44, 45). At the suggestion of Ferdinand Reich, Clemens Winkler made a thorough study of the metal and its compounds (20). 

The use of zinc sulfate to catalyze the potassium ferricyanide oxidation procedure251 is worthy of comment. It is possible that other metals would also catalyze this oxidation, but their presence in the system would have a deleterious effect on thfe fluorescence of the final product, while Zn++ ions have relatively little effect. For instance, Cu++ ions would be expected to catalyze the oxidation stage, but they would also have a strong quenching effect on the fluorescence of the final products.144 Some of the Zn++ ions will also presumably be removed from the solution as insoluble zinc ferro-cyanide. Anton and Sayre have recently questioned the value of zinc sulfate as a catalyst at low pH.252... 

Estimation of Selenium in Sulphide Minerals.s—In various sulphite-cellulose manufactories difficulties have occurred which have been traced to the presence of selenium in the pyrites used for burning. Part of the selenium remains in the burnt pyrites and part volatilises with the sulphur dioxide. 20 to 30 grams of pyrites are dissolved in hydrochloric acid (dens.=1-19) and potassium chlorate. Zinc is added to reduce the iron to the ferrous condition more hydrochloric acid is then added, the solution boiled and stannous chloride added to precipitate selenium. Since the selenium may contain arsenic, it is collected on an asbestos filter, dissolved in potassium cyanide and reprecipitated using hydrogen chloride and sulphur dioxide. The element may then be estimated by the iodometric method described below. In order to determine the relative proportion of volatile to non-volatile selenium, the pyrites may be roasted in a current of oxygen. After this treatment the contents of the tube are dissolved in warm potassium cyanide and the selenium reprecipitated and estimated in the ordinary way. 

Phosphate buffer (0.6 M) slightly inhibited lipolysis, but the same concentration of borate and barbiturate buffers was without effect. Zinc chloride, potassium cyanide, manganese sulfate, cysteine, and magnesium chloride retarded milk lapse activity to various degrees. All of these compounds were tested at pH 8.5 with tributyrin as substrate during a 30-min incubation period (Peterson et al 1948). 

The greatest tonnage decrease in cyanide plating has occurred lor zinc plating. As of this writing, less than one-third of all zinc is plated Irom cyanide baths. The remainder is plated from alkaline noncyunidc. zinc potassium chloride, and zinc ammonium chloride balhs. 

A typical bath is based on stannate and cyanide for 80% tin, the solution is made using 120 g/L potassium stannate, 11.3 g/L zinc cyanide, and 30 g/L potassium cyanide. The bath is operated at 65°C with cathode current of 100—800 A/m2 and anode current of 150—250 A/m2. Anodes are the same composition as the alloy, and have to be filmed properly as for stannate tin plating. 

A low tin alloy, more correctly 90% zinc—tin alloy, has been proposed as an economical solderable substitute for cadmium. For this 10% tin deposit, the same type of plating bath, but using 40 g/L tin, 15 g/L zinc, 15 g/L potassium cyanide, and 45 g/L free potassium hydroxide is used. 

The sulfide ores are commonly roasted with sodium chloride to form AgCl, which is then dissolved by leaching the ore with an aqueous solution of sodium or potassium cyanide. The chloride is dissolved because of the formation of soluble sodium silver cyanide [NaAg(CN)2]. The cyanide solution is treated with finely divided zinc, which displaces the silver from the complex cyanide. 

Copper (I) iodide is a dense, pure white solid, crystallizing with a zinc-blende structure below 300°. It is less sensitive to light than either the chloride or bromide, although passage of air over the solid at room temperature in daylight for 3 hours results in the liberation of a small amount of iodine. It melts at 588°, boils at 1,293°, and unlike the other copper halides, is not associated in the vapor state. Being extremely insoluble (0.00042 g./l. at 25°), it is not perceptibly decomposed by water. It is insoluble in dilute acids, but dissolves in aqueous solutions of ammonia, potassium iodide, potassium cyanide, and sodium thiosulfate. It is decomposed by concentrated sulfuric and nitric acids. 

Funazo et al. [812] have described a method for the determination of cyanide in water in which the cyanide ion is converted into benzonitrile by reaction with aniline, sodium nitrite and cupric sulphate. The benzonitrile is extracted into chloroform and determined by gas chromatography with a flame ionisation detector. The detection limit for potassium cyanide is 3 mg L 1. Lead, zinc and sulphide ion interfere at lOOmg L 1 but not at lOmgL-1. 

The palladium-catalyzed, microwave-assisted conversion of 3-bromopyridine to 3-cyanopyridine using zinc cyanide in dimethylformamide (DMF) has been reported <2000JOC7984>. Substoichiometric quantities of copper or zinc species improve both conversion rate and efficiency of Pd-catalyzed cyanation reactions <1998JOC8224>. A modification of this procedure uses a heterogeneous catalyst prepared from a polymer-supported triphenylphosphine resin and Pd(OAc)2 the nitriles were obtained from halopyridines in high yields <2004TL8895>. The successful cyanation of 3-chloropyridine is observed with potassium cyanide in the presence of palladium catalysts and tetramethylethylenediamine (TMEDA) as a co-catalyst <2001TL6707>. 

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