Alum Solution

Add a known volume ofo oaM.AgNOj solution (in excess) and boil the solution until the silver chloride has coagulated. Filter through a conical 5 cm. funnel, ensuring that the filter-paper does not protrude above the r m of the funnel. Wash the silver chloride and the filter-paper several times with a fine jet of distilled water. To the united filtrate and washings add i ml. of saturated ferric alum solution. The solution should be almost colourless if it is more than faintly coloured, add a few drops of concentrated nitric acid. Then titrate with 0 02M-ammonium thiocyanate solution until the permanent colour of ferric thiocyanate is just perceptible. (Alternatively the chloride may be determined potentiometrically.)... 

Values are for neutral alum solutions commercial alum liquor contains excess H2SO and values mn about 0.5 pH units lower slightly basic alum solutions, some excess AI2O2, have values of about 0.5 pH units higher. 

FRP, plastics (polyvinyl chloride, polyethylene, polypropylene, and other similar materials), and rubber are general use and are recommended for alum solutions. Care must be taken to provide adequate support for these piping systems, with close attention given to spans between supports so that objectionable deflection will not be experienced. The alum solution should be injected into a zone of rapid mixing or turbulent flow. 

Pulp and Paper Technical Association of Canada - Standards of Sulphite Waste Liquor, C-3, Jan. 68. Viscosity of Sulphite Waste Liquor, C-4,Jan. 68. F-2, Nov. 70. Wire Screening, F-3, July 92. Alum Solutions, F-4, Jan. 68, http //WWW. paptac.ca/english/engdatsh.htm. 

GARNET - WEDC/publications/wares. Discusses soda ash and alum solutions. Go to the following web site http //www.lboro.ac.uk... 

Alaun-karmin, m. Micros.) alum carmine, -kies, m. aluminous pyrites, -kuchen, m. alum cake, -lauge,/. alum liquor, -leder, n. alum leather, -losung, /. alum solution, -mehi, -ptilver, n. powdered alum, precipitated alum. 

Calculate how much 0.200 M Ba(N03)2 would be needed to totally precipitate all of the sulfate ion present in the alum solution. 

Add bentonite, alum, and anionic polymer to the synthetic wash water. The dosage was 2 L of powdered bentonite clay, 100 ml of 10 N N OH, 20 ml of 57% alum solution and 25 ml of anionic polymer. 

The mixed alum solution, on treatment with ammonia or potassium carbonate, forms carbonates of potassium, rubidium and cesium. Rubidium carbonate is separated from other alkab metal carbonates by fractional crystal-bzation (see Rubidium)... 

The formation of rnonodisperse amorphous, spherical particles of chromium hydroxide is offered here as an example. These dispersions are readily obtained by simply heating chrome alum solutions (35). It was established experimentally that the sulfate ion was essential in order to obtain uniform dispersions thus, when chromium nitrate solutions were aged, monodispersed particles were produced only if a sulfate salt was introduced into the reaction. 

Figure 1.1.19 illustrates such hematite particles coated with chromium hydroxide in which the latter was produced by the hydrolysis of a chrome alum solution in the presence of a-Fe203 cores on aging the dispersion at 85°C. For greater efficiency the chromium salt solution was either preheated or preheated with KOH (but avoiding precipitation of chromium hydroxide) (144). 

Isolate the polymer by freezing-thawing or by adding alum solution and boiling the mixture. 

AMMONIA ADDED TO ALUM SOLUTION GIVES ALUMINUM HYDROXIDE. BUT THIS DOES NOT DISSOLVE IN MORE AMMONIA. 

A solution of iron alum, containing about 14 gms. per litre, and acidified with sulphuric acid until the solution assumes a pale straw colour, is prepared. By titrating 25 c.cs. of this with titanous chloride, using potassium thiocyanate as indicator, its strength is determined, and as it will retain its strength for a long period, this alum solution may be used in all subsequent cases for standardising the titanous chloride solution. 

If the filtrate is yellowish and not reddish, the absence of colouring matter is at once concluded. With a reddish filtrate, about one-third of this is treated in a cylinder with a few drops of alum solution and then slight excess of ammonia if after a rest of some hours the precipitate is red, the presence of carmine is indicated. 

Paper-sizing Test.—100 grams of the powdered colophony are shaken with 20 parts of crystallised sodium carbonate and 150 parts of water it is noted whether the mixture is homogeneous and of a milky white or other colour. Finally, alum solution is added and the colour of the precipitate formed observed. 

The precipitate (tannate of iron) is dissolved in dilute sulphuric add and the solution thus obtained extracted with ethyl acetate, the ethereal liquid being then separated from the aqueous solution and evaporated to dryness. The residue (tannic add) is dissolved in water and identified by means of dilute ferric sulphate or ferric alum solution (blackish-blue coloration). If the ink contains logwood, part of this passes with the tannin in such case, to identify the tannin in the aqueous solution of the ethyl acetate extract, distinctly alkaline ammoniacal copper sulphate is added, this giving a pretipitate in presence of tannin. 

Resistance to Alum.—01 gram of the ultramarine is shaken with 10 c.c. of 10% alum solution, the value of the ultramarine increasing with the length of time it retains its colour under these conditions. 

Then add the following solution (including precipitate) slowly to the hypo-alum solution while stirring the latter rapidly ... 

The silver nitrate should be dissolved completely before adding the sodium chloride immediately afterward, add the solution containing the milky white precipitate to the hypo-alum solution. The formation of a black precipitate in no way impairs the toning action of the bath if adequate agitation is used. 

The haematoxylin is dissolved in 95% ethanol and to 6 ml of a 17% solution is added 100 ml saturated ammonium alum solution and 0.5 g mercuric oxide. After boiling and cooling 25 ml of glycerol and 25 ml of methanol are added and the whole mixture filtered. 

For compounds containing chlorine or bromine, a weighed sample is dissolved in 10 ml. of methanol 10 ml. of 20% sodium hydroxide, 2 g. of zinc, and 0.5 g. of Raney nickel are added, and the mixture is heated with reflux for 1 hour over a water bath. It is then cooled and decanted. After acidification with nitric acid, 20 ml. of standard silver nitrate solution and 5 ml. of a ferric alum solution are added, and the solution is titrated with standard potassium thiocyanate. The procedure is modi-... 

Flame-retardant additives are often used to make polymers more fire resistant. Already in ancient times flame-retardants were applied during the siege of Piraeus in 83BC wooden assault towers were treated with an alum solution in 1638 Sabatini s book "The risk of fire in theatres" was published, where the preparation of flame-retardant coulisses is described and Montgolfier impregnated his hot-air balloons with alum ("Technische Winkler Prins Encyclopedic", Deel 2, Elsevier, Amsterdam, 1976, in Dutch). 

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