Isolation Liquid gold

In some cases the soluble material is distributed in small isolated pockets in a material which is impermeable to the solvent such as gold dispersed in rock, for example. In such cases the material is crushed so that all the soluble material is exposed to the solvent. If the solid has a cellular structure, the extraction rate will generally be comparatively low because the cell walls provide an additional resistance. In the extraction of sugar from beet, the cell walls perform the important function of impeding the extraction of undesirable constituents of relatively high molecular weight, and the beet should therefore be prepared in long strips so that a relatively small proportion of the cells is ruptured. In the extraction of oil from seeds, the solute is itself liquid. 

The lack of homopolyatomic anions for elements to the left of group IV In Table I is noteworthy. Zlntl reported no success with reactions of alkali metal alloys of the copper and zinc family elements and of thallium with liquid ammonia, and the generally stabilizing effect of crypt has not been evident In our own Investigations of alloys of mercury and thallium. On the other hand. It is possible to Isolate a white crypt-potassium gold compound from ammonia solutions at low temperatures which decomposes to elemental gold (+ ) above about -10°C (30). 

Radon can be isolated from radium by several methods. An aqueous solution of radium salt such as radium bromide is heated, liberating radon. Radioactive bombardment then decomposes water to oxygen and hydrogen. Radon is separated from the gaseous mixture by condensation in tiny tubes placed in liquid air. The tubes then are sealed by melting. A gold or platinum coating is applied to form the radon seeds used in radiation therapy. 

Other aqueous preparative methods include aerial oxidation of an alkaline solution of CoS04 and NaCNO to give the fulminatocobaltate(III) anion [Co(CNO)6]3-, reduction of ruthenate(VI) by excess of fulminate to give [Ru(CNO)6]4, and displacement of 2,2 -bipyridyl or 1,10-phenan-throline from nickel(II) or cobalt(III) complexes to give [Ni(CNO)4]2 or [Co(CNO)6]3. Liquid ammonia may replace water as solvent [Ni(NH3) ]2+ and [Co(NH3)6]3+, for example, react with sodium fulminate in this solvent to form [Ni(CNO)4]2 and [Co(CNO)6]3. In all these reactions fulminate behaves very like cyanide with [AuClJ-, however, reduction to form the gold(I) complex [Au(CNO)2] takes place and no gold(III) complex can be isolated. 

In the present study, gold and tin were usually evaporated simultaneously from two separate crucibles, and the atoms cocondensed simultaneously with a high excess of the vapor of the solvent of choice. This resulted in the almost complete matrix isolation of the atoms at -196°C (the ratio of Au Sn could be determined by weighing the used crucibles later). Upon warming the atom clustering took place, mainly in the cold liquid solvent as it melted. 

Auric sulphate, Aua(S04)3.—The sulphate has not been isolated. Gold dissolves in concentrated sulphuric acid in presence of a small proportion of nitric acid, forming a yellow liquid, but dilution reprecipitates the gold, either as the hydroxide, or in presence of reducers as the metal.8 The nitric acid can be replaced by other oxidizers, such as iodic acid9 and manganese dioxide10 and a solution of the sulphate is also formed by the action of concentrated sulphuric acid on auric oxide.11... 

Chlorine was the first halogen to be isolated and sodium chloride, common salt, has been known from early times as being essential to the human diet as such it has been mentioned in the Bible. Aqua regia, a mixture of hydrochloric and nitric acids, has been known since the thirteenth century as a liquid for dissolving the very inert metal, gold. The ancient color mentioned in the Bible as purple has been identified as a brominated organic compound, namely 6,6-dibromoindigo, which used to be extracted from a small snail. 

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