Copper sulphate anhydrous

Required Anthranilic acid, 20 g. anhydrous sodium carbonate, 7 5 g, sodium nitrite, 12 g. concentrated hydrochloric acid, 190 ml. crystalline copper sulphate, 50 g. concentrated ammonia, 85 ml, hydroxylamine hydrochloride, 14-5 g. (or hydroxylamine sulphate, 17-4 g.) acetic acid, 10-20 ml,... 

Required Arsenious oxide, 27 g. aniline, 20 ml. (20 g.) anhydrous sodium carbonate, 55 g. crystalline copper sulphate,... 

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°. 

To appreciate the action of a drying agent of class (a), let us imagine some anhydrous copper sulphate in an evacuated vessel provided with a pressure gauge, and water is allowed to enter slowly the temperature is assumed constant at 25°. The results may be best expressed by means of a vapour pressure - composition diagram (Fig. 7, 20, 1). The initial system is represented by the point A the pressure will rise along AB until the monohydrate CuS04,H20 commences to form at B. 

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. 

Benedict s solution Is prepared as follows. Dissolve 86-5 g. of crystallised sodium citrate (2Na,C,H(0, l 1H,0) and 50 g. of anhydrous sodium carbonate in about 350 ml. of water. Filter, if necessary. Add a solution of 8-65 g. of crystallised copper Sulphate in 50 ml. of water with constant stirring. Dilute to 500 ml. The resulting solution should be perfectly clear if it is not, pour it through a fluted filter paper. 

Chlorobenzene. Prepare a solution of phenyldiazonium chloride from 31 g. (30 -5 ml.) of aniUne, 85 ml. of concentrated hydrochloric acid, 85 ml, of water, and a solution of 24 g. of sodium nitrite in 50 ml. of water (for experimental details, see Section IV,60). Prepare cuprous chloride from 105 g. of crystallised copper sulphate (Section 11,50,1), and dissolve it in 170 ml. of concentrated hydrochloric acid. Add the cold phenyl diazonium chloride solution with shaking or stirring to the cold cuprous chloride solution allow the mixture to warm up to room temperature. Follow the experimental details given above for p-chlorotoluene. Wash the chlorobenzene separated from the steam distillate with 40 ml. of 10 per cent, sodium hydroxide solution (to remove phenol), then with water, dry with anhydrous calcium chloride or magnesium sulphate, and distil. Collect the chlorobenzene (a colourless liquid) at 131-133° (mainly 133°), The yield is 29 g. 

Concurrently with the preparation of the phenyldiazonium chloride solution, prepare a cold suspension of sodium arsenite. Place 250 ml. of water in a 3-htre round-bottomed flask equipped with a mechanical stirrer. Heat the water to boding, add 125 g. of anhydrous sodium carbonate, and, as soon as the carbonate has dissolved, introduce 62 5 g. of pure arsenious oxide and 3 g. of crystallised copper sulphate with stirring. When all the solids have dissolved, cool the solution with stirring under a stream of tap water until the temperature has fallen to 15°. 

Observe its action upon anhydrous copper sulphate. 

The first one-third of this tube may be filled with anhydrous copper sulphate to remove any hydrogen sulphide or hydrogen chloride present from sulphides or chlorides in the limestone. 

Hydroxylamine combusts in contact with anhydrous copper sulphate. 

Urea was treated with oxalic acid and carbon. The operation was carried out in the presence of anhydrous copper sulphate in order to detect the water formed, and gases were expected to bubble through a barium hydroxide solution to be able to see carbon dioxide. Unfortunately, the apparatus was closed by mistake. It detonated due to the large quantity of gases formed in the reaction ... 

Heat is liberated when adding water to anhydrous copper sulphate because a new crystal lattice forms in response to strong, new bonds forming between the water and Cu2+ and SO2- ions. As corroborative evidence of a change in the crystal structure, note how anhydrous copper sulphate is off-white but the pentahydrate is blue. 

Put about 0.01 g of anhydrous copper sulphate and several crystals of potassium iodide into a dry porcelain mortar. Mix these substances with a pestle, and then triturate them. What do you observe Add a few drops of water to the mixture. Explain the observed phenomena. Write the equation of the reaction. 

Separate the chloroform from the water with the aid of a separatory funnel. To purify the chloroform, place it into a separatory funnel and pour in a 2% sodium hydroxide solution. Mix the liquid well by shaking it. Separate the chloroform layer. Repeat the operation, replacing the sodium hydroxide solution with water. Dry the chloroform over anhydrous copper sulphate. 

Copper (II) sulphate (anhydrous). Suitable for esters and alcohols. Preferable to sodium sulphate in... 

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

Water. — On shaking 20 cc. of ether in a stoppered flask with 1 gm. of anhydrous copper sulphate, the latter should not acquire a green or blue color. 

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