Potassium Aluminium Alum

Prepare hot saturated solutions of aluminium and potassium sulphates. To do this, dissolve 6.66 g of aluminium sulphate crystallohydrate in 5 ml of hot (/ 70 °C) water. Calculate what amount of potassium sulphate is equimolecular to 6.66 g of the aluminium sulphate crystallohydrate. Weigh this amount of potassium sulphate and dissolve it in 10 ml of hot water. Pour the potassium sulphate solution into that of aluminium sulphate. Cool the solution, filter off the precipitated crystals, dry them between sheets of filter paper, weigh them, and determine the yield of the substance in per cent. Examine the shape of the crystals under a microscope and draw them. 

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Filter off the formed crystals and dry them on filter paper. Choose a well formed crystal of the alum, fasten it with the aid of a thin thread or hair to a glass rod and lower it into the mother liquor. Watch how the crystal grows several days. Examine the shape of the chromium potassium alum crystals under a microscope and compare it with that of potassium aluminium alum crystals. What will happen if crystals of potassium aluminium alum are lowered into a saturated solution of chromium potassium alum. 

Materials Potassium aluminium alum, potassium chromium alum. 

Directions (a) Dissolve 16 grams of potassium aluminium alum in 100 c.c. of hot water, filter if necessary, and cool the solution to room temperature in running water. Shake occasionally for five minutes 8 grams of finely powdered potassium chromium alum with 100 c.c. of water at about 30°. The temperature should not be allowed to go higher than 35° in order to prevent the change of the chromium salt to the green modification. Filter the solution. In four beakers place the following (1) 40 c.c. of the solution of aluminium alum and 10 c.c. of the chromium alum, (2) 20 c.c. of the former and 10 c.c. of the latter, (3) the rest of the solution of the former and (4) the rest of the solution of the latter. 

Fig. 81.—Composition of Solution and Solid Mixtures of Potassium Chromium and Potassium Aluminium Alums.

Fig. 82.—Vapour Pressures of Mixtures of Potassium Chromium in Potassium Aluminium Alums.

The complex dehydration processes of potassium aluminium alum have been followed by t.g.a., A -ray diffraction, and i.r. methods. ... 

Nishide, T. and Tsuchiya, R. (1965) Formation of Al " -SO ion-pair in an aqueous solution of potassium aluminium alum. Bull. Chem. Soc. Jpn., 38, 1398-1400. 

In addition to their energetic value, oil shales have also been used as sources for other materials, such as alumina, ammonium sulphate, phosphate, sodium carbonate, S, U, V, and Zn (Murray 1974). In the early 17th century, potassium aluminium sulphate was extracted from the Alum Shales in Sweden for use in the tanning and textile industry. It was only by the 19th century that hydrocarbons were being extracted from these Alum Shales while, in the 1960s, their content of U and V was being exploited (Dyni 2000). 

Potassium aluminium sulphate (Alum) A1K(S04)2T2 H20 precipitates the aqueous immunogen solution/suspension is mixed with 0.3 vol 10% alum. The pH is then adjusted to about 8.0 with sodium hydroxide solution and the resultant precipitate washed in 0.154 M NaCl solution and administered. 

Chromium in its Compounds is sometimes metallic and sometimes non-metallic toward the other components. Thus, in chromium trioxide, CrOg, the anhydride of the hypothetical chromic acid, H2Cr04, chromium acts as a non-metal, just like sulphur in sulphuric acid hence in chromates the chromium is acidic, or non-metallic, in its chemical relations with the other elements. In chromic compounds, however, chromium acts as a metal. Thus chromium hydroxide, Cr(OH)3, is analogous to aluminium hydroxide chrome alum is potassium chromium sulphate, and is analogous to aluminium alum. The two classes pass into each other by appropriate operations,... 

Potassium aluminium sulfate (Alum) A1K(S04)2.12H20 The aqueous immunogen solution/suspension is mixed with 0.3 vol 10% alum. The pH is then ac usted to about 8.0 with sodium hydroxide solution and the resultant precipitate washed in 0.9% NaCl solution and administered. Acetone precipitates The aqueous immunogen is precipitated with 4.5 vol of acetone at -20°C for 1 h. The precipitate is collected by centrifugation at lO.OOOg at room temperature, washed in 80% acetone, and air-dried. The pellet is resuspended in saline using a Dounce homogenizer and then administered directly or in association with... 

Arrhenius parameters for the dehydrations of ammonium and potassium aliuninium alums [38] were in agreement with the Polanyi-Wigner equation. Comparisons of the shapes of nuclei on different crystal surfaces indicated that reaction proceeds along (100) planes. The observed decrease of the rate in water vapour is attributed to the blocking of pores by adsorbed molecules. No intranuclear cracking was apparent and the product-reactant boimdaries became irregular because of the influence of water on reorganization of the product phase. The appearance of these nuclei contrasted markedly with those in mixed potassium chromium/aluminium alums, where there is an approximately concentric structure. 

Materials Sodium bicarbonate, potassium acid tartrate, sodium aluminium alum, primary calcium phosphate, starch, commercial baking powder. 

The octahedral, cubic crystals are violet to black in colour, and appear ruby-red in thin layers and J. H. Kastle found that the intensity of the colour is very much reduced at liquid air temp. F. Klocke, C. F. Rammelsberg, C. von Hauer, and J. W. Retgers showed that the crystals are isomorphous with other alums, for they show similar corrosion figures. E. Dittler obtained overgrowth with potassium aluminium sulphate. T. V. Barker found a close connection between parallel overgrowths in chrome-alum, potash-alum, and ammonia-alum and the mol. vols which are respectively 542-2, 541-6, and 552-2. C. von Hauer found that with the introduction of a crystal of iron-alum in a sat. soln. of chrome-alum nearly all the latter separates out while L. de Boisbaudran found that a sat. soln. of basic ammonium aluminium alum does not affect the octahedral faces of the... 

The introduction of compoimds for retention and drainage in the paper industry began with the invention of rosin sizing through Moritz Illig 1807 in Darmstadt/Germany. Rosin size is made of tall or tree resins, which are either soponified with caustic soda or dispersed with protective colloids. The rosin size was at first fixed to fibre with potash alum, a double salt of aluminium and potassium aluminium sulphate. Later on aluminium sulphate was... 

Merrifield (1849) describes how alumine zuccarino was alum (potassium/aluminium sulfates) groimd and heated with rose water, sugar and white of egg and allowed to harden by cooling. It was used as a base for lake pigments and in the preparation of verdigris qq.v.). 

According to Kiilm and Curran (1986), during the nineteenth century Baltimore chrome yellow was likely to have contained calcium sulfate and lead sulfate (qq.v.), or, according to Mierzinski (1881), alum (hydrous potassium aluminium sulfate, KA1[S04]2.12H20). They state that the term is now applied to a pale chrome yellow precipitated on gypsum or asbestine (q.v.). 

Kiihn and Curran (1986), citing Mierzinski (1881), indicate that old forms of this pigment consisted of chrome yellow (. v.) and alum, a hydrous potassium aluminium sulfate. The same pigment mixture is also given for Spooner s chrome yellow and Baltimore chrome yellow q.v.) by the same source. 

Heaton and Hurst do not appear to say the same thing, though Heaton is a revision of the text by Hurst. Bristow (1996b) states that Hurst says it is made from calcium sulfate and aluminium sulfate, adding that he thinks that it was made with alum (potassium aluminium sulfate) as opposed to aluminium sulfate. 

MULVEY B, LANDOU ML, BUSCH RA. Effects of potassium aluminium sulphate (alum) used in an Aeromonas salmonicida bacterin in Atlantic salmon, Salmo salar L. / Fish Dis 1995,18,495-506. 

Aluminium potassium sulfate (I2H2O, alum) [7784-24-9] M 474.4, m 92°. Crystd from weak aqueous H2SO4 (ca 0.5mL/g). 

Note. Prepare the precipitating reagent by dissolving 5.0 g aluminium potassium sulphate (potash alum) in 90 mL warm water. Cool and add dropwise with stirring, while cooling in ice, a solution of 2.0 g sodium hydroxide in 5.0 mL water until the initially formed precipitate re-dissolves. After standing for 12 hours, filter, adjust the pH to 12.6, and dilute to 100 mL with water. 

Theory The solution of potassium alum is heated with an excess of disodium edetate to ensure complete formation of aluminium-edetate complex. Hexamine serves as a buffer thereby stabilizing the pH between 5 and 6, the ideal pH for the titration of the disodium edetate not required by the A1 with 0.05 M lead nitrate employing xylenol orange as indicator. The various reactions involved may be represented by the following equations ... 

The rate Oi diffusion.—In order to find if the components of a double salt are dissociated in soln.—say, alum K SO. A SO saq.v K SOa+A SO g+Aq.— T. Graham 3 assumed that the dissociated parts would diffuse with different velocities, and he found that potassium and aluminium sulphates diffused at different rates from an aq. soln. of potash alum into the pure solvent. Hence, he assumed that alum is partially dissociated into its constituents when in aq. soln. He likewise inferred that the components of the double sulphates of potassium and copper, and of potassium and magnesium, are not dissociated in aq. soln. since under the same conditions there is no sign of any difference in the rates of diffusion of the components. E. Fischer and E. Schmidmer 4 determined the relative quantities of the components of double salts which were drawn up by capillary attraction into rolls of filter paper. If a double salt is dissociated a larger proportion of the more diffusible component ascends the paper. Dissociation is far more pronounced in aq. than in alcoholic soln. 

G. S. Serullas treated potassium chlorate with an excess of hydrofluosilicic acid the clear liquid was decanted from the sparingly soluble potassium fluosilicate, the soln. evaporated below 30°, and filtered through glass powder J. J. Berzelius evaporated the acid liquid mixed with finely divided silica below 30° in air, or over cone, sulphuric acid and potassium hydroxide in vacuo. The excess of hydrofluoric acid was volatilized as silicon fluoride, and the clear liquid was then filtered from the excess of silica. R. Bottger treated sodium chlorate with oxalic acid whereby sparingly soluble sodium oxalate was formed J. L. Wheeler, and T. B. Munroe treated sodium chlorate with hydrofluosilicic acid and M. Brandau treated potassium chlorate with aluminium sulphate and sulphuric acid and precipitated the alum so formed with alcohol. Chloric acid is formed in many reactions with hypochlorous and chlorous acid for example, it is formed when an aq. soln. of chlorine or hypochlorous or chlorous acid decomposes in light. It is also formed when an aq. soln. of chlorine dioxide stands in darkness or in light. A mixture of alkali chlorate and chlorite is formed when an aq. soln. of an alkali hydroxide is treated with chlorine dioxide. 

Aluminium Potassium Alum. Put about 2 g of aluminium potassium alum into a test tube containing 3 ml of water. Does the alum dissolve in this amount of water in the cold If it doesn t, heat the contents of the tube almost to boiling. What is observed Let the solution cool. What happens How does the solubility of the alum change with a change in the temperature ... 

Acquaint yourself with the appearance of aluminium potassium alum, sodium chloride, and calcium acetate crystals using a microscope. To do this, transfer a drop of the relevant solution containing a few crystals onto a slide. Cover the liquid with a cover glass and place the preparation on the microscope stage. Draw the shape of the crystals. 

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