Ferric potassium alum

Ferric potassium alum, K2S04.Fe2(S04)3.24H20, may be obtained by mixing together concentrated solutions of potassium and ferric sulphates in the requisite proportions and allowing to stand for some days at 0° C., when the salt crystallises out in violet octahedra. 

Eisen-alaun, m. iron alum (ferric potassium sulfate), -amiant, m. (Iron) fibrous silica.. ammonaiauQ, m. ammonium ferric alum.. ammonaiaunldsuQg, /. solution of ammonium iron salt, esp. ammonium ferric alum. -antimonerZ) n., -antimonglanz, m. berthier-ite. 

The term alum, itself, refers to potassium alum, potassium aluminum sulfale, KA1(S04)2 12H O. Oilier common alums are ferric ammonium alum, NH4 Fe(S02)2 12HiO. and sodium chrome alum, NaCr(SOa)212ITO. 

Cond Chem Dict( 1956),279 Potassium-Iron Alum (Ferric Potassium Sulfate or Iron Alum), K2S04. Fe2(S04)j7 24H20, mw 1006.5, mp 33°, d 1.806. Prepd by mixing equi molecular amts of ferric and K sulfate and cor.eg the soln spontaneously. It forms fine violet octahedra crysts, liable to decomp to a brown deliquescent mass. Iron alum is sol in w, insol in ale. This... 

Potassium ferri-sulphite, KFe(S03)S04, is prepared by the action of potassium hydrogen sulphite upon ferric ammonium alum. It crystallises in slender needles, which are sparingly soluble in cold water. With hot water, ferrous and potassium sulphates pass into solution, leaving an insoluble yellow residue. 

When ferric ammonium alum and potassium ferricyanide are acted upon with hydrogen peroxide in the presence of free hydrochloric acid, a blue substance, Fe7(CN)18.10H2O, is obtained, having properties similar to Williamson s violet, but less stable towards dilute ammonium hydroxide.7... 

About 2 gm. benzyl iodide are weighed into a flask and then 50 ml. 20% alcoholic potash solution are added and the mixture refluxed for about an hour. At the completion of the saponification the contents of the flask are allowed to cool and then transferred to a 500-ml. flask and made up to volume with water. 100 ml. of the resulting solution are placed in a distillation flask and distilled in steam after adding 10 gm. ferric ammonium alum and acidifying with sulphuric acid. By this treatment, the ferric salt is converted to the ferrous condition, liberating iodine which is distilled over into 5% potassium iodide solution. At the end of the distillation, the free iodine in the potassium iodide solution is titrated with a decinormal solution of sodium thiosulphate. From this, the amount of iodine and so the quantity of benzyl iodide in the sample may be calculated. 

Potash. See Potassium carbonate Potash alum. See Potassium alum dodecahydrate Potassium alum anhydrous Potash blue. See Ferric ferrocyanide Potash chlorate. See Potassium chlorate Potash lye. See Potassium hydroxide Potash sulfurated. See Sulfurated potash Potassa. See Potassium hydroxide Potassic ascorbate. See Potassium ascorbate Potassium... 

Black haw (Viburnum prunifolium) bark extract Ferric chloride hexahydrate Ferrous sulfate anhydrous Hops (Humulus lupulus) extract Lead acetate trihydrate Pansy (Viola tricolor) extract Picric acid Potassium alum anhydrous Potassium alum dodecahydrate Sage (Salvia officinalis) Sodium alum Sodium chlorate Tannic acid Wintergreen (Gaultheria procumbens) oil ... 

Dimethylaminoethyl acrylate methyl chloride quat. Dimethylaminoethyl methacrylate dimethyl sulfate quat. Dimethylaminoethyl methacrylate methyl chloride quat. Dimethyl diallyl ammonium chloride Ferric chloride Ferric chloride hexahydrate Ferrous sulfate heptahydrate Guar (Cyanopsis tetragonoloba) gum Hectorite Hydrogenated tallow 1,3-propylene diamine Kaolinite Potassium alum dodecahydrate Sodium aluminate coagulant, yarn processing Polyquaternium-6... 

Potassium alum anhydrous Potassium alum dodecahydrate 233-149-7 Ferric phosphate 233-156-5 n-Butyl thioglycolate 233-162-8 Anthium Dioxcide Aquabon Chlorine dioxide 233-163-3... 

In 1863 R. C. Bottger of Frankfort-on-the Main found that thallium occurs in some spring waters. A certain salt mixture from Nauheim contained, in addition to the chlorides of sodium, potassium, and magnesium, those of cesium, rubidium, and thallium. Since he was able to prepare a thallium ferric alum exactly analogous to potassium ferric alum, he regarded thallium as an alkali metal (72, 73). Although it is sometimes univalent like sodium and potassium, it is now classified in Group III of the periodic system. 

Chlorides, bromides, and iodides can be quantitatively determined by treatment with silver nitrate, and, with suitable precautions, the precipitated halide is washed, dried, and weighed. Chlorides in neutral soln. can be determined by F. Mohr s volumetric process 27 by titration with a standard soln. of silver nitrate with a little potassium chromate or sodium phosphate as indicator. When all the chloride has reacted with the silver nitrate, any further addition of this salt gives a yellow coloration with the phosphate, and a red coloration with the chromate. In J. Volhard s volumetric process, the chloride is treated with an excess of an acidified soln. of silver nitrate of known concentration. The excess of silver nitrate is filtered from the precipitated chloride, and titrated with a standard soln. of ammonium thiocyanate, NH4CN8—a little ferric alum is used as indicator. When the silver nitrate is all converted into thiocyanate AgN03-fNH4CNS=AgCNS +NH4NOS, the blood-red coloration of ferric thiocyanate appears. 

Potassium-Iron Alum (Fetric Potassium Sulfate or Iron Alum), KaS04. Fea(S04)3 24HaO, mw 1006.5, mp 33°, d 1.806. Prepd by mixing equi molecular amts of ferric and... 

As a preliminary, ferric sulfate is made by the oxidation of ferrous sulfate. Dissolve 100 g. of ferrous sulfate in 100 cc. of boiling water, to which has been added before heating 10 cc. of sulfuric acid. Add concentrated nitric acid portionwise to the hot solution, until a diluted sample gives a reddish-brown (not black) precipitate with ammonia. This will require about 25 cc. Boil the solution down to a viscous liquid to get rid of excess nitric acid, dilute to about 400 cc., and add the calculated weight of ammonium sulfate. The crystallization is conducted as in the former exercise, preferably under 20°. By the addition of potassium sulfate, the corresponding potassium iron alum may be secured. In this case, it is necessary to concentrate the solution until there is about four parts of water to one of the hydrated alum and cool to about zero to secure crystallization. Both of these alums are amethyst in color, the potassium salt being much less stable and having a rather low transition point. 

This energetic reducing agent can be maintained at constant strength in aqueous hydrochloric acid solution for a reasonable period. It is advisable, however, to re-standardise it after 24 hours standing. It serves for the reduction of aromatic nitro compounds, some nitroso bodies, many azo dyes, and of nearly all the dyes which yield leuco-compounds. It is easily standardised against a ferric salt—say ferric alum—using potassium thiocyanate as indicator. From the equations —... 

L. P. de St. Gilles, and I. M. Kolthoff, found that potassium permanganate oxidizes hypophosphorous acid completely to phosphoric acid. L. Amat found that the oxidation proceeds more quickly the more cone, the soln., the more acidic the soln., and the higher the temp. at ordinary temp., and in dil. soln., the oxidation is incomplete. If the soln. be too hot, some permanganate may be decomposed without interaction with the hypophosphorous acid. The reaction was studied by I. M. Kolthoff. M. Major, and A. Sieverts found that reduced iron readily dissolves in a hot soln. of sodium hypophosphite ferric salts are reduced to the ferrous state and ferric alum reacts at the temp, of the water-bath, while phosphorous acid is not attacked after several hours. 

A 0.5-g. sample is dissolved in 50 ml. of 3 M aqueous ammonia, and the solution is made slightly acidic to litmus paper with 6 M nitric acid. Fifty milliliters of standard 0.1 M silver nitrate, 3 ml. of nitrobenzene, and 10 drops of ferric alum indicator are added, and the excess Ag+ is titrated with 0.1 M potassium thiocyanate to a brownish-red end point. 

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-... 

Abundant yellow or white salt crusts are present on waste rock and at the surface of the soil. The crusts comprise alum-like sulfate minerals containing variable amounts of sodium, potassium, iron and aluminium, such as the mineral jarosite. They are often very soluble in water, releasing acid and precipitating ferric hydroxides. 

Volumetric estimation4 in neutral solution can be effected by titration with standard sodium chloride, potassium chromate being employed as indicator and in nitric-acid solution with thiocyanate, using ferric alum as indicator, or with sodium chloride without any external indicator. 

In a back-titration of silver by chloride ions, potassium chromate can be used to indicate the endpoint (Mohr s method) but with potassium thiocyanate as tifrant, anunonium iron(III) sulfate ( ferric alum ) is preferred. In the direct titration (Gay-Lussac s method) the location of the turbidimetric endpoint has been improved in detail. ... 

Chemical properties of iron. Passivity. Ferrous compounds ferrous sulfate, ferrous ammonium sulfate, ferrous chloride, ferrous hydroxide, ferrous sulfide, ferrous carbonate. Ferric compounds ferric nitrate, ferric, sulfate, iron alum, ferric chloride, ferric hydroxide, ferric oxide (rouge, Venetian red). Potassium ferro-cyanide, potassium ferricyanide, Prussian blue. 

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