Ammoniacal copper solution

A portion of the extract is dissolved in three parts of hot water, ammonia in slight excess being then added. The precipitate formed is filtered off and the cold filtrate treated with excess of a freshly prepared ammoniacal copper solution (100 c.c. of 13% copper sulphate solution mixed with 150 c.c. of ammonia solution and 300 c.c. of 14% caustic soda solution). 

An important process is the manufacture of regenerated cellulose applied to make fibers (e.g., rayon) and films (e.g., Cellophane). Solvents used classically in cellulose regeneration are a mixture of carbon disulfide and sodium hydroxide or ammoniacal copper solutions. More recent solvents include N-methylmorpholine-N-oxide and phosphoric acid [4]. The cellulose solution is extruded through nozzles into an acidic precipitation bath and is spun into fibers. Recently, the partly toxic and strongsmelling solvents have been replaced by ionic liquids which are even able to improve the solubility of the slightly soluble cellulose [10]. For example, 1 1 of l-butyl-3-methylimidazolium chloride dissolves lOOg of cellulose at 100°C [11],... 

Ammoniacal copper solutions lose their blue color when put in contact with the extracted ash, and the copper cannot be removed from the material by subsequent extraction with strong ammonia. 

A series of standard ammoniacal copper solutions was prepared and the transmittance measured. The following data were obtained ... 

John Mercer (Dean or Great Harwood, nr. Bolton, Lancs., 21 February 1791-Oakenshaw, Lancs., 30 November 1866), a calico-printer, discovered mercerising (1844), the use of potassium ferrocyanide and potash for the discharge of indigo (1848), the use of arsenates as a substitute for phosphates in dunging the manufacture of sodium stannite and stannate, stannous sulphate from tin and copper sulphate solution, Turkey-red oil, the solubility of cellulose in ammoniacal copper solution, and blue-print photography. He taught himself chemistry from a second-hand copy of the Chemical Pocket-Book of James Parkinson, of Hoxton Square, London (2 ed. 1801, 3 ed. 1803). ... 

Whereas conventional gravimetric cellulose determination is complicated and time-consuming, cellulose concentrations can be determined rapidly in ammoniacal copper solution by measuring the optical rotation of the levorotatory solution. However, the solutions must be completely free of turbidity [138]. 

The sensitive color reaction of iron with a,a -dipyridyl or phenanthroline cannot be employed directly in the presence of much copper because a faint pink would be hidden in the blue solution. Furthermore, Cu+ ions consume these reagents to give ammine ions. The detection of iron in the presence of much Co+ or Ni+ ions is not feasible for the same reasons. Procedure (I) given here for the detection of little iron in the presence of much copper makes use of the fact that thioglycolic acid discharges the blue of ammoniacal copper solutions. The redox reaction is ... 

The carbon dioxide was washed out of the process gas with water at high pressure and could eventually be recovered as a useful byproduct Residual carbon monoxide was usually removed with an ammoniacal copper solution before the final stage of ammonia synthesis. 

The solid readily dissolves chemically in concentrated hydrochloric acid, forming a complex, and in ammonia as the colourless, linear, complex cation [H3N -> Cu <- NHj] (cf AgCl) if air is absent (in the presence of air, this is oxidis to a blue ammino-copper(II) complex). This solution of ammoniacal copper(I) chloride is a good solvent or carbon monoxide, forming an addition compound CuCl. CO. H2O, and as such is used in gas analysis. On passing ethyne through the ammoniacal solution, a red-brown precipitate of hydrated copper(I) dicarbide (explosive when dry) is obtained ... 

Cuprous chloride, ammoniacal this solution is used for the same purpose and is made in the same manner as the acid cuprous chloride above, except that the acid solution is treated with ammonia until a faint odor of ammonia is perceptible. Copper wire should be kept with the solution as in the acid reagent. 

The second ceUulosic fiber process to be commercialized was invented by L. H. Despeissis (4) in 1890 and involved the direct dissolution of cotton fiber in ammoniacal copper oxide Uquor. This solvent had been developed by M. E. Schweizer in 1857 (5). The cuprammonium solution of ceUulose was spun into water, with dilute sulfuric acid being used to neutralize the ammonia and precipitate the ceUulose fibers. H. Pauly and co-workers (6) improved on the Despeissis patent, and a German company, Vereinigte Glanstoff Eabriken, was formed to exploit the technology. In 1901, Dr. Thiele at J. P. Bemberg developed an improved stretch-spinning system, the descendants of which survive today. 

The best protection for wood against the attack of decay fungi, insects, or marine borers is obtained by applying preservatives under pressure before installation (61,62). Both oil-type preservatives, such as creosote or petroleum solutions of pentachlorophenol, and waterborne preservatives, such as copper-chrome arsenate and ammoniacal-copper arsenate, are used when wood is to be in direct contact with the ground or in the marine environments. 

Metal Extraction. As with other carboxyhc acids, neodecanoic acid can be used in the solvent extraction of metal ions from aqueous solutions. Recent appHcations include the extraction of zinc from river water for deterrnination by atomic absorption spectrophotometry (105), the coextraction of metals such as nickel, cobalt, and copper with iron (106), and the recovery of copper from ammoniacal leaching solutions (107). 

Senanayake, G. (2012). Gold leaching by copper(II) in ammoniacal thiosulphate solutions in the presence of additives. Part I A review of the effect of hard-soft and Lewis acid-base properties and interactions of ions. Hydrometallurgy, 115-116, 1-20. doi 10.1016/j. hydromet.2011.11.011... 

Cuprammonium A process for making regenerated cellulose fibers. Cellulose, from cotton or wood, is dissolved in ammoniacal copper sulfate solution (Schweizer s reagent, also called cuprammonium sulfate). Injection of this solution into a bath of dilute sulfuric acid... 

As Umezaki and Iwamoto [42] have reported that organic mercury can be reduced directly with stannous chloride in the presence of sodium hydroxide and copper II, the determination of organic mercury can be simplified, particularly if the reagent used for back-extraction does not interfere with the reduction of organic mercury. Matsunga and Takahasi [43] found that extraction with an ammoniacal glutathione solution was satisfactory. 

Although S-diketones cannot compete with hydroxyoximes for the extraction of copper from acid media, they do have advantages for extraction from ammoniacal leach solutions because, unlike hydroxyoximes, they do not transfer ammonia. The extraction follows Eq. (11.6), and the extent of extraction depends on the concentration of ammonia and ammonium salts. 

Copper(I) acetylide is prepared by passing acetylene gas over an aqueous solution of ammoniacal copper salt ... 

Cyanamide, colorless crystals, m.p. 40°, is readily soluble in water, alcohol, and ether. An aqueous solution of cyanamide gives a black precipitate of copper cyanamide with ammoniacal copper sulfate solution, and a yellow precipitate of silver cyanamide with ammoniacal silver nitrate. The precipitates are almost unique among the compounds of copper and silver in the respect that they are insoluble in ammonia water. 

The precipitate (tannate of iron) is dissolved in dilute sulphuric add and the solution thus obtained extracted with ethyl acetate, the ethereal liquid being then separated from the aqueous solution and evaporated to dryness. The residue (tannic add) is dissolved in water and identified by means of dilute ferric sulphate or ferric alum solution (blackish-blue coloration). If the ink contains logwood, part of this passes with the tannin in such case, to identify the tannin in the aqueous solution of the ethyl acetate extract, distinctly alkaline ammoniacal copper sulphate is added, this giving a pretipitate in presence of tannin. 

A solution of indigotin or of ammoniacal copper sulphate to determine the titre of the hydrosulphite these are prepared thus ... 

The reducing agent (a solution containing cupro-ammonia ions) is first prepared. Dissolve 63 g (0.25 mol) of crystallised copper(n) sulphate in 250 ml of water in a 1-litre beaker, add 100 ml of concentrated ammonium hydroxide solution (d 0.88) and cool the solution to 10 °C. Dissolve 17.8 g (0.256 mol) of hydroxylammonium chloride or 21 g (0.256 mol) of hydroxylammonium sulphate in 60 ml of water, cool to 10 °C and add 42.5 ml of 6 m sodium hydroxide solution if the resulting solution of hydroxylamine is not clear, filter it at the pump. Without delay add the hydroxylamine solution, with stirring, to the ammoniacal copper(n) sulphate solution. Reduction occurs at once, a gas is evolved and the solution assumes a pale blue colour. Protect the reducing agent from the air if it is not used immediately. 

A pilot plant on recovery of copper from ammoniacal etching solutions was run with a good performance, as described in refs. [186,187]. LIX54 in kerosene was used as the membrane phase in SLM. Large pilot-plant HF contactors Liqui cel (diam. 25.4 cm, length 71.1 cm) with surface area of 130 m2 have also been used [186]. 

Toshio [23] determined copper in hot spring waters by cation exchange chromatography in ammoniacal pyrophosphate solution. A procedure may be included to overcome iron interference. 

The reaction is not disturbed by silver or copper, or by iron(III), chromium or aluminium in the presence of ammoniacal tartrate solution if zinc is present, ammonium chloride should first be added cobalt(III) ions represss the sensitivity and should be oxidized to the tervalent state with hydrogen peroxide iron(II) interferes and should be oxidized and alkaline tartrate solution added before applying the test. 

Perhaps the most extensive area of research in simple pretreatment systems to enhance the weathering properties of wood has involved application of inorganic salt solutions. Much of the early work in this field was undertaken at the U.S. Forest Products Laboratory in Madison, Wisconsin and was aimed at improving the performance of transparent finishes. Black [25] described an experimental chromate-based wood finish and Black and Mraz [26] discovered that both acid and ammoniacal-copper chromate treatments significantly improved the performance of clear finishes on western red cedar, redwood (Sequoia sempervirens), and Douglas fir plywood. Later research [27] demon-... 

Many of the classical methods grew out of the earliest synthesis of imidazole, which was achieved in 1858 by Debus [1] when he allowed glyoxal, formaldehyde and ammonia to react together. Although the earliest modifications of this method used a-diketones or a-ketoaldehydes as substrates [2, by the 1930s it was well established that a-hydroxycarbonyl compounds could serve equally well, provided that a mild oxidizer (e.g. ammoniacal copper(ll) acetate, citrate or sulfate) was incorporated [3. A further improvement was to use ammonium acetate in acetic acid as the nitrogen source. All of these early methods have deficiencies. There are problems associated with the synthesis of a wide range of a-hydroxyketones or a-dicarbonyls, yields are invariably rather poor, and more often than not mixtures of products are formed. There are, nevertheless, still applications to the preparation of simple 4-alkyl-, 4,5-dialkyl(diaryl)- and 2,4,5-trialkyl(triaryl)imidazoles. For example, pymvaldehyde can be converted quite conveniently into 4-methylimidazole or 2,4-dimethylimidazole. However, reversed aldol reactions of pyruvaldehyde in ammoniacal solution lead to other imidazoles (e.g. 2-acetyl-4-methylimidazole) as minor products [4]. Such... 

This salt crystallizes in thick columns with four molecules of water. Its chief use is as a reducing agent. It reduces an ammoniacal silver solution and in this way is used in silvering glass. It is also used as a constituent of Fehling s solution, (p. 332), which is an alkaline copper solution reduced by certain sugars. It acts as a purgative in Seidlitz powders which consist of sodium-potassium tartrate, sodium acid carbonate and free tartaric acid. 

Prepare a small ion exchange column using 10 cm of SAC resin. H or Na form). The resin is converted to the ammonium form by pas.sing 2 BV of 2 N ammonium sulfate solution slowly through the bed followed by a rin.se with deionized water. Two bed-volumes of ammoniacal copper sulfate solution (0.25 M CUSO4/2.5 M NH OH) is passed through the column which converts the resin to the intense blue copper(ll) tetrammine form, R.) Cu(NHi)4 The resin is rinsed and stored in a tightly stoppered bottle. 

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