Aluminium sulphate

Describe the laboratory preparation, from aluminium, of (a) anhydrous aluminium chloride, (b) potassium aluminium sulphate dodecahydrate. 

Why is potassium aluminium sulphate not soluble in benzene A compound M has the composition C = 50.0% H=12.5%o A1 = 37.5%. 0.360 g of M reacts with an excess of water to evolve 0.336 1 of gas N and leave a white gelatinous precipitate R. R dissolves in aqueous sodium hydroxide and in hydrochloric acid. 20 cm of N require 40 cm of oxygen for complete combustion, carbon dioxide and water being the only products. Identify compounds N and R, suggest a structural formula for M, and write an equation for the reaction of M with water. (All gas volumes were measured at s.t.p.)... 

Aluminium Building materials Corrosion to aluminium sulphate (white)... 

M = Al, Ga, In, Tl). The solution chemistry of Al in particular has been extensively investigated because of its industrial importance in water treatment plants, its use in many toiletry formulations, its possible implication in both Altzheimer s disease and the deleterious effects of acid rain, and the ubiquity of Al cooking utensils.For example, hydrated aluminium sulphate (10-30 gm ) can be added to turbid water supplies at pH 6.5-7.5 to flocculate the colloids, some 3 million tonnes per annum being used worldwide for this application alone. Likewise kilotonne amounts of A1(OH)2.5C1o.5 in concentrated (6m) aqueous solution are used in the manufacture of deodorants and antiperspirants. 

Many salts which are corrosive towards unalloyed iron because of their tendency to hydrolyse to release acid, e.g. calcium and zinc chlorides, are not dangerous to high-chromium irons. The more corrosive salts, typified by aluminium sulphate and ferric chloride, are, however, corrosive to high-chromium irons. Hot aluminium sulphate solutions can give corrosion rates greater than 1 27 mm/y although cold solutions corrode the alloys at rates not exceeding 0-127 mm/y. 

Mendeleev predicted that eka-boron sulphate is less soluble than aluminium sulphate. This is not the case. 

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... 

Sodium aluminium sulphate Sodium bisulphate Sodium hypochlorite Sodium perchlorate Sodium thiocyanate Stannic ammonium chloride Stannic chloride Stannous chloride Uranyl nitrate Zinc chloride Zinc fluorosilicate... 

Aluminas. Aluminas, porous AI2O3, are available in many forms. They constitute the most important carrier material in heterogeneous catalysis. Alumina is amphoteric and, as a con.sequence, soluble in both acidic and basic media. Precipitation can be performed from an acid solution by adding a base or from a basic solution by adding an acid, as schematically represented in Fig. 3.18. If, for example, at a pH of less than about 3 a base is added to an aqueous solution of aluminium sulphate, a precipitate is formed. If this material is filtered, dried and calcined, an amorphous porous AI2O3 is obtained. At other pH values different porous aluminas can be synthesized. 

Aluminium borohydride Aluminium chloride Aluminium chlorate Ammonium tetrachloroaluminate Aluminium fluoride Aluminium trihydroxide Aluminium ammonium sulphate Aluminium potassium sulphate Aluminium nitride Aluminium nitrate Sodium aluminate Aluminium sodium aluminate Aluminium phosphate Aluminium phosphide Aluminium borate Aluminium oxychloride Aluminium fluorosilicate Aluminium magnesium silicate Aluminium sulphate... 

To examine the cavitational effect of ultrasound on bright-red complex of aluminon adsorbed on Al(OH)3, in our experiments, 25 ml of 0.005 M aluminium sulphate was treated with 5 ml of 1% aluminon (triammonium aurine-tricarboxylate). This adsorption complex was sonicated for 10, 20 and 30 min, while the control sample was agitated for the same duration with a magnetic stirrer. The turbidity in sonicated sample increased, as time of sonication increased compared to the unsonicated condition (Table 9.18 and Fig. 9.4). In sonicated sample, the colour of the adsorption complex was dark compared to the control sample and the settlement of the adsorption complex was also slower due to the smaller size particle of the complex. 

In another experiment, different volumes (2.5, 5.0 and 10.0 ml) of 4,000 ppm solution of sodium acetate was added to 10.0 ml of 1,000 ppm solution of aluminium sulphate. In the normal reaction, no precipitate was obtained in cold and neutral solutions, but on boiling with excess reagent, a voluminous precipitate of basic aluminium acetate, Al(OH)2COOCH3, was formed. 

The turbidity gradually increased as shown in Table 9.19, with an increase in the volume of solution or amount of CH3COONa in all samples (control, sonicated and boiled). But the increase in precipitation was not in proportion to the reagent added to the A12(S04)3 solution. The turbidity in the first solution for unsonicated, sonicated and boiled solution was roughly in the ratio 1 lVi 3. Turbidity in sonicated and boiled samples was almost equal in solution containing 10 ml of aluminium sulphate and 5.0 ml of sodium acetate. Turbidity in sonicated samples (10 + 10) increased marginally compared to the boiled sample. This trend of sonicated samples, as seen in Table 9.19, indicated the role of ultrasonic power to be important. When 20 ml of A12(S04)3 solution was mixed with 5 ml of sodium acetate and sonicated, the amount of precipitate formed was negligible compared to the precipitation in a mixture of 10 ml of A12(S04)3 and 2.5 ml of sodium acetate, where the intensity of the ultrasonic power was almost double. 

Dimethyl-p-phenylenediamine (7-6 g.) is dissolved in 70 c.c. of iV-hydrochloric acid, and 35 g. of zinc chloride in 50 c.c. of water are added. With good stirring 12 g. of aluminium sulphate in 20 c.c. of water and then 15 g. of sodium thiosulphate in 20 c.c. of water are poured in. To the solution thus obtained one-third of a solution of 16 g. of sodium dichromate in 30 c.c. of water is at once added and the temperature of the solution is raised as rapidly as possible to 40°. The addition of 6 g. of dimethylaniline dissolved in 8 c.c. of concentrated hydrochloric acid follows, and finally the remainder of the oxidising agent is poured in. Of course, all these solutions are prepared before the experiment is begun. 

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