Ammonium-Copper Sulphate

Preparation of a Hydrated Double Salt Ammonium-Copper Sulphate, (NH SOpCuSCVe O 

Besides forming molecular compounds with water (hydrates) certain salts have the property of combining with a second salt either with or without water. In these combinations the character of the individual salts is somewhat modified but not completely changed. Hence the name, double salts . In physical properties such as crystalline form, solubility, and, in some cases, color, the crystals of the double salt differ from those of the simple salts. These compounds follow the law of definite proportions. 

Ammonium sulphate crystallizes from solution as the anhydrous salt, (NH4) 2SO4 j copper sulphate as the hydrate, CuS04-5H20 but when equivalent amounts of the two salts are in solution together the double salt, (NH SCh-CuSCh-fiH, separates first because it is less soluble than either of the single salts. 

Materials copper sulphate, CuS04-5H20,50 grams = 0.2 F.W. 

5-inch funnel and filter paper, iron ring and ring stand. 

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Read the preliminary discussion which precedes the preparation of ammonium-copper sulphate, page 61. 

Preparation 3 illustrated the formation of a double salt, ammonium copper sulphate, (NH SCh-CuSCh-OI O. In the double salt, ammonium plays the part of a positive radical. In the present preparation ammonia plays an altogether different role. It does not possess a primary valence, and it enters into a molecular compound with the salt by virtue only of a secondary valence. In fact, the ammonia in this preparation is held in the same sort of a combination as the water in the hydrate CuS04-5H20. The molecules of ammonia would appear to be bound to the copper rather than to the sulphate radical, because when the salt is dissolved in water the four ammonia molecules remain in combination with the copper as the complex ion Cu(NH3)4++, while the sulphate radical appears as the ordinary SO4 ion. Thus we might say that this salt is the sulphate of the ammonio-copper complex. (Cf. Ammoniates, page 118.)... 

Cobalt ammonium Copper sulphate Sulphuric acid... 

Solubility of Mixed Crystals of Potassium Copper Sulphate AND Ammonium Copper Sulphate in Water. 

The special reducing agent (a solution containing cupro-ammonia ions) is first prepared. Dissolve 63 g. of crystallised copper sulphate in 250 ml. of water in a 1-Utre heaker, add 100 ml. of concentrated ammonium hydroxide solution (sp. gr. 0-88), and cool the solution to 10°. Dissolve 17 8 g. of hydroxylammonium chloride or 21 g. of hydroxylammonium sulphate in 60 ml. of water, cool to 10°, and add 42 -5 ml. of QN sodium hydroxide solution if the resulting solution of tydroxylamine is not clear, filter it at the pump. Without delay add the hydroxylamine solution, with stirring, to the ammoniacal cupric 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. 

This is in agreement with the suggestion of Vreudge et al. [11], Plack et al [7], and Siyam et al. [19,20]. Copper sulphate forms crosslinked structures with ammonium groups of p(AM-DAA-HCl) and p(AM-DAEA-HCl) are shown in the possible Structure 25 and Structure 26 , respectively. 

Chemical deposition Simple immersion deposits of copper may be obtained on iron and steel in a solution containing, for example, 15 g/1 of copper sulphate and 8 g/1 sulphuric acid, and on zinc-base alloy in a solution containing copper sulphate 300 g/1, tartaric acid 50 g/1 and ammonium hydroxide 30ml/l . Such deposits are thin and porous and are mainly plated for their colour, e.g. for identification, or for their lubricating properties, e.g. in wire drawing. 

Procedure (copper in crystallised copper sulphate). Weigh out accurately about 3.1 g of copper sulphate crystals, dissolve in water, and make up to 250 mL in a graduated flask. Shake well. Pipette 50 mL of this solution into a small beaker, add an equal volume of ca AM hydrochloric acid. Pass this solution through a silver reductor at the rate of 25 mL min i, and collect the filtrate in a 500 mL conical flask charged with 20 mL 0.5M iron(III) ammonium sulphate solution (prepared by dissolving the appropriate quantity of the analytical grade iron(III) salt in 0.5M sulphuric acid). Wash the reductor column with six 25 mL portions of 2M hydrochloric acid. Add 1 drop of ferroin indicator or 0.5 mL N-phenylanthranilic acid, and titrate with 0.1 M cerium(IV) sulphate solution. The end point is sharp, and the colour imparted by the Cu2+ ions does not interfere with the detection of the equivalence point. 

Aluminium sulphate Ammonium bifluoride Ammonium bisulphite Ammonium bromide Ammonium persulphate Antimony trichloride Beryllium chloride Cadmium chloride Calcium hypochlorite Copper nitrate Copper sulphate Cupric chloride Cuprous chloride Ferric chloride Ferric nitrate... 

Almonds Brown rot Greasy spot Altemaria alternata Xanthomonas arboricola Copper ammonium carbonate, copper sulphate... 

Tomatoes Blight Phytophthora infestans Bordeaux mixture, copper ammonium carbonate, copper oxychloride, copper sulphate + sulphur... 

Ammonium chloride buffer, pFH 7.5 - dissolve 400 g ammonium chloride (NH4CI), 40 g EDTA disodium salt, 40 g sodium dihydrogen phosphate dihydrate (NaH2P04.2FH20) and 0.08 g copper sulphate pentahydrate (CUSO4.5H2O) in 1400 ml previously heated water (5 min in a domestic microwave) contained in a 3-1 beaker. Adjust the pFH to 7.5 0.1 with 10% w/v NaOH and make up to 2 I. 

H. M. Dawson and J. McCrae, D. P. Konowaloff, and W. Gaus also used soln. of various salts of the alkali metals, and of potassium, sodium, cupric, or barium hydroxide in place of water and also copper sulphate, copper chloride, zinc sulphate, and cadmium iodide while M. 8. Sherrill and D. E. Russ examined the effect of ammonium chromate. W. Herz and A. Kurzer examined the distribution of ammonia between water and a mixture of amyl alcohol and chloroform. Observations on the distribution of ammonia between water and chloroform were made by T. S. Moore and T. F. Winmill, G. A. Abbott and W. C. Bray, and J. M. Bell. J. H. Hildebrand gave for the molar fraction N X104 of ammonia at 1 atm. press., and 25°, dissolved by ethyl alcohol, 2300 methyl alcohol, 2730 and water, 3300. 

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