Copper sulphate hydrated

Add in turn 55 g. of anhydrous sodium carbonate, 27 g. of powdered arsenious oxide and i g. of hydrated copper sulphate to 175 ml. of water in a 2 litre beaker, and heat the stirred mixture until an almost clear solution is obtained then immerse the stirred solution in ice-water, and cool it to 5°. 

We may now understand the nature of the change which occurs when an anhydrous salt, say copper sulphate, is shaken with a wet organic solvent, such as benzene, at about 25°. The water will first combine to form the monohydrate in accordance with equation (i), and, provided suflScient anhydrous copper sulphate is employed, the effective concentration of water in the solvent is reduced to a value equivalent to about 1 mm. of ordinary water vapour. The complete removal of water is impossible indeed, the equilibrium vapour pressures of the least hydrated tem may be taken as a rough measure of the relative efficiencies of such drying agents. If the water present is more than sufficient to convert the anhydrous copper sulphate into the monohydrate, then reaction (i) will be followed by reaction (ii), i.e., the trihydrate will be formed the water vapour then remaining will be equivalent to about 6 mm. of ordinary water vapour. Thus the monohydrate is far less effective than the anhydrous compound for the removal of water. 

Cuprous chloride. Hydrated copper sulphate (125 g.) and sodium chloride (32-5 g.) are dissolved in water (400 ml.) boiling may be necessary. An allialine solution of sodium sulphite (from 26 5 g. of sodium bisulphite and 17 -5 g. of sodium hydroxide in 200 ml. of water) or the solution of the sodium bisulphite alone is added to the resulting hot solution during about 5 minutes with constant shaking. The solution will be decolourised or nearly so. It is then cooled to room temperature (or in an ice bath), and the supernatant liquid is decanted... 

Different samples of aqueous solution containing radionuclides of Co and Eu were prepared at different copper sulphate concentrations and constant polymer concentrations (pAM) of 15 mg/1. The addition of salt to the system was done to reduce both the repulsion forces between the radionuclides and the interaction between the polymeric chains [7]. The polymer efficiency for the prepared samples was determined, results are shown in Fig. 15. It is clear that the polymer efficiency for Eu " is higher than for Co. This can be explained by the difference in the tightly bound structured water associated with different cationic species [14,107]. On this basis, we expect that Co is more hydrated than Eu. This is due to the difference in the ionic size. The hydra-... 

Hydrated salts, as a rule, do not make good standards because of the difficulty of efficient drying. However, those salts which do not effloresce, such as sodium tetraborate Na2B407, 10H2O, and copper sulphate CuS04,5H20, are found by experiment to be satisfactory secondary standards.2... 

Addition of water-absorbing substances, e.g. anhydrous salts that readily form hydrates, such as anhydrous copper sulphate. 

Add copper sulphate solution and then excess caustic soda solution. Solution turns violet, but precipitation of copper hydrate does not take place. On warming, reduction of the cupric compound occurs and red cuprous oxide is precipitated (Trammer s test). 

An acid of sp. gr. 1-517 at 15°/4° absorbs 0-88 per cent, of nitric oxide so that the coefi. of absorption is 12-5. The speed of absorption varies with the cone, of the acid. C. A. Winkler obtained no absorption of nitric oxide by the hydrate of sulphuric acid and M. Berthelot said that nitric oxide is very slightly soluble in cone, sulphuric acid. O. Lubarsch made some observations on this subject. E. Desbassayns de Richemont said that if the sulphuric acid contains a little ferrous sulphate, nitric oxide imparts to it a red colour and if copper sulphate, a violet colour. In the latter case, W. Manchot found that the coloration is due to the formation of an easily dissociated copper nitrosylsulphate, CuSO4.NO— vide infra. For the corresponding compound with ferrous sulphate, vide infra. G. Lunge found that 1 c.c. of sulphuric acid of sp. gr. 1-84 absorbs 0-035 c.c. of nitric oxide, and an acid of sp. gr. 1-50, 0-017 c.c. and O. F. Tower, v vol. of nitric oxide at 760 mm. absorbed by one vol. of acid 18° and H2S04 per cent. 

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

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. 

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.)... 

Iron is apt to be troublesome when present in quantities of 1 part per 100,000 and upwards. The metal oxidises, and hydrated oxide (rust) precipitates out on standing this may block the pipes conveying the water. This oxidation is assisted by certain lowly organisms known as iron bacteria.1 Iron salts are not toxic, but have a certain medicinal value and impart a bitter taste to the water. Copper salts are frequently employed to remove algae, 0-3 parts per 100,000 being about the minimum effective concentration of copper sulphate for this purpose. At such dilutions the salt is not prejudicial to the human organism. 

Definitions. — Crystals which have lost water of crystallization are said to be Dehydrated or Anhydrous. Thus the bluish white product obtained by heating the blue crystallized copper sulphate is usually called dehydrated copper sulphate. The words dehydrated and anhydrous have been extended to mean any substance from which water has been removed, as anhydrous alcohol or ether. The opposite term Hydrated is sometimes applied to a compound to emphasize the fact that it contains water of crystallization. The term Dissociation is applied to that special kind of decomposition in which the components may reunite under favorable conditions. If crystallized copper sulphate is heated, water, which is driven off by heat, readily reunites with the copper sulphate to form the blue crystallized compound, which, strictly speaking, is copper sulphate united with water, though it is loosely called copper sul-... 

Alcohols are commonly dried with quicklime. Water is usually removed from basic substances by treating them with solid potassium hydroxide. Anhydrous copper sulphate is an excellent drying agent for most substances another salt, anhydrous sodium sulphate, is frequently used. It must be remembered in the latter case that hydrated sodium sulphate loses its water of crystallization at 33° it is evident that the salt acts as a drying agent only below this temperature. 

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