Preparation of Anhydrous Copper Nitrate

Preparation of Anhydrous Copper Nitrate. Prepare 7-10 ml of liquid nitrogen(IV) oxide (see Fig. 86a). If the oxide has solidified, 

After 10-12 hours, decant the solution from the unreacted copper shavings into vessel 1 (Fig. 92fe). Connect the vessel via trap 2 and empty wash bottle 5 to a water-jet pump. Open clamps 4 and 5, 

When no liquid remains in vessel 7, close clamp 4, open clamp 5, close the cock of the water-jet pump, and disconnect vessel 1. In a dry chamber, extract the powdered anhydrous copper nitrate from the vessel and put it into a weighed weighing bottle. Calculate the yield in per cent. 

Indicate the position of phosphorus in Mendeleev s periodic table of the elements, its electron configuration, the size of its atom, and its oxidation states. 

Perform all experiments with white and red phosphorus, and also with hydrogen phosphide in a fume cupboard. White phosphorus is poisonous and readily ignites. Work with it requires special care. Handle white phosphorus only with pincers. Carry phosphorus to your workplace only in a porcelain bowl or in a mortar with water. 

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Fig. 92. Preparation of anhydrous copper nitrate a—setup for reacting metallic copper with nitrogen(IV) oxide in ethyl acetate 6—apparatus for distilling off the solvent...

If a cylinder of dinitrogen tetroxide is available, prepare anhydrous copper(II) nitrate. Preparation of anhydrous copper(II) nitrate... 

Summary Copper fulminate is prepared in a similar fashion as the mercury salt by the addition of a hot nitrate acid solution upon ethyl alcohol. In this case, anhydrous copper nitrate is dissolved in nitric acid, the mixture is then heated, and the ethanol dropped in. As the reaction proceeds, the copper fulminate will precipitate. It is then easily filtered-off, washed, and dried. Note Various modifications to this procedure exist. 

Cu(N03 )26H2 0, is produced by crystallization from solutions below the transition poiat of 26.4°C. A basic copper nitrate [12158-75-7] Cu2(N02)(0H)2, rather than the anhydrous product is produced on dehydration of the hydrated salts. The most common commercial forms for copper nitrate ate the ttihydtate and solutions containing about 14% copper. Copper nitrate can be prepared by dissolution of the carbonate, hydroxide, or oxides ia nitric acid. Nitric acid vigorously attacks copper metal to give the nitrate and evolution of nitrogen oxides. 

Cupric nitrate (3H2O) [10031-43-3 (3H2O) 3251-23-8 (anhydr)] M 241.6, m 114 , b 170 (dec), d 2.0. Crystd from weak aqueous HNO3 (0.5mL/g) by cooling from room temperature. The anhydrous salt can be prepared by dissolving copper metal in a 1 1 mixture of liquid NO2 and ethyl acetate and purified by sublimation [Evans et al. J Chem Soc, Faraday Trans 1 75 1023 1979], The hexahydrate dehydr to trihydrate at 26°, and the anhydrous salt sublimes between 150 and 225°, but melts at 255-256° and is deliquescent. 

Attempts to prepare the anhydrous nitrate by dehydration always fail because of decomposition to a basic nitrate or to the oxide, and it was previously thought that Cu(N03)2 could not exist. In fact it can be obtained by dissolving copper metal in a solution of N2O4 in ethyl acetate to produce Cu(N03)2.N204, and then driving off the N2O4 by heating this at 85-100°C. The observation by C. C. Addison... 

The nitrate salt prepared by this method is hydrated. It cannot be dehydrated fully without decomposition. Anhydrous CuNOs may be prepared by dissolving copper metal in a solution of dinitrogen tetroxide, N2O4, in ethyl acetate. Upon crystaUization, an N2O4 adduct of Cu(N03)2 that probably has the composition [NO [Cu(N03)3] is obtained. This adduct, on heating at 90°C, yields blue anhydrous copper(II) nitrate which can be sublimed in vacuum at 150°C and coUected. 

It is likely that as further anhydrous nitrates are prepared, further examples of such behavior will be found. Certain ruthenium nitrates also give nitrite on hydrolysis (28). All metal nitrates which by their covalent bonding can release NO2 radicals during reaction need not necessarily give nitrite on hydrolysis the latter is a complicated process which involves the coordination chemistry of the metal. For example, copper nitrate gives only nitrate ions in aqueous solution, but its reactions with ethers are at present interpreted on a free-radical basis. 

Recently, Field and Hardy (1962) have shown that copper and other anhydrous, volatile nitrates can be prepared from the anhydrous chlorides of the respective metals by treating them with an excess of dinitrogen pen-toxide. The chlorine is evolved as NOgCl and the excess of reagent and the co-ordinated oxides of nitrogen are removed by warming the product. The method is of general application and has enabled volatile Zr(NOg)4 to be made. 

Ionic reactions between solvo-acids and solvo-bases may lead to insoluble products such as thallium sulphate formed from mercury(II) sulphate and thallium bromide in molten mercury(II) bromide. Similarly anhydrous copper(II) sulphate can be prepared by using a copper(II) halide. Perchlorates, nitrates and phosphates of many other elements can be prepared in a similar manner. By allowing mer-cury(II) oxide to react with the sulphate in mercury(II) bromide solution a red, insoluble product of composition (Hg0)2HgS04 is formed. Analogous compounds are formed from the sulphide, selenide and telluride of mercury in molten mercuric bromide. 

Curtius and Rissom [41] prepared cupric azide by the action of an aqueous solution of sodium azide on an aqueous solution of cupric sulphate, obtaining the salt in a hydrated form. The anhydrous salt was prepared by Straumanis and Ciru-lis [125] in the form of dark brown, reddish sediment by reaction of lithium azide on cupric nitrate in an alcohol solution. Another method described by Curtius consists of reacting hydrazoic acid with metallic copper in an aqueous medium. 

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