Chromium chloride 4- hydrate

A solution of 26.8 g. of green chromium chloride hydrate [CrCl3(1130)4] Cl 2 H3O in an equal amount of water Is allowed to stand for 24 hours at room temperature, and a mixture of 10 g. of cone. H3SO4 and 4 g. of water is then added. The sulfate soon separates in bright green tablets. 

Green, crystalline chromium chloride hydrate [CrCl3(H30) 4] Cl 2 HgO and somewhat more than the stoichiometric quantity of urea are dissolved in some water and treated with a few drops of HCl. The solution is concentrated in a drying oven at 75 °C (or on the steam bath) until a crystalline crust forms. The crystal slurry thus obtained is dissolved in the minimum quantity of water at 50-60°C and rapidly filtered. The salt complex separates as green needles. 

Green chromium chloride hydrate [CrCl3(OHg)4]Cl 2 HgO is converted into [CrCl3(OHg)4]Cl on standing for 3 days in a vacuum desiccator over cone. H3SO4. It is then suspended In absolute ether [CrCl3(OHa)3] is formed by disproportionation and dissolves with a brown-violet color. On evaporation of the ethereal solution in the absence of atmospheric moisture, [CrCl3(OH3)3] is obtained as an amorphous brown powder. 

This analogue is easily prepared by evaporating the equivalent quantities of chromium chloride 6-hydrate and ammonium thiocyanate in aqueous solution to dryness on the steam bath and extracting the residue with absolute alcohol. Evaporation of the alcoholic extract yields the red salt. 

Methods for the preparation of tris(ethylenediamine)rhodium-(III) chloride hydrate and for its resolution by means of the diastereoisomer Ii (—)D-lRh(en)s] (- -)-tart 2 3H20 are presented. The resolution of tris(ethylenediamine)chromium(III) chloride by means of an analogous diastereoisomeric compound is also described. 

When the apparatus has been flushed, a boiling solution of 16 g. (0.20 mol) of anhydrous sodium acetate dissolved in 35 ml. of water is added through E A slow nitrogen flow is maintained, and a solution of 9 g. (0.034 mol) of chromium(III) chloride 6-hydrate in 15 ml. of 0.4 N sulfuric acid is poured into the top of the redactor. The rate of flow of the chromium solution can be controlled by stopcock B. If too fast a rate is used, there is a possibility of incomplete reduction. Distilled water is poured after the chromium chloride until the effluent is only slightly colored by chromium. This requires approximately 125 ml. 

Derivation (1) Interaction of solutions of chromium chloride and sodium phosphate (2) by mixing chrome alum and disodium hydrogen phosphate. Violet, amorphous powder (not the hexahydrate) is formed that becomes crystalline on contact with water. On boiling, it is converted into green crystalline hydrate. 

In connection with the chrome tanning of leather it has been found in technical practice that by the addition of neutral salts it is possible to use more basic chrome liquors The added salt prevents the precipitation of hydrated chromium oxide This phenomen has been regarded as due to an actual increase in hydrogen ion concentration It is much more probable, however, that we are dealing with an increase of activity rather than an increase of mere concentration Instead of dealing with the complex system presented in the tanning bath we shall refer briefly to the results obtained by Thomas and Miss Baldwin loc at) in the chemically better defined case of a solution of chromium chloride... 

Fig. 314. Dehydration of chromium (III) chloride hydrate with carbon tetrachloride.

A solution of 90 g. of green chromium (III) chloride hydrate in 120 ml. of water and 30 ml. of 2 N H3SO4 is poured into the re-ductor tube and its outflow rate so adjusted that only a pure light blue chromium (II) salt solution drops into the reaction vessel... 

Chromic acid strontium salt Chromic acid strontium salt (1 1). See Strontium chromate Chromic acid, zinc salt. See Zinc chromate Chromic anhydride. See Chromium trioxide Chromic chloride. See Chromium chloride (ic) Chromic chloride stearate. See Stearatochromium chloride complex Chromic fluoride. See Chromium fluoride (ic) Chromic hydrate Chromic hydroxide Chromic (III) hydroxide. See Chromium hydroxide (ic) Chromic nitrate. See Chromium nitrate Chromic oxide. See Chromium oxide (ic) Chromic oxide hydrated. See Chromium hydroxide green... 

C6H2nCl3CrN5 3 H2O, DL-Tris(ethylenediamine)chromium(IIl) chloride hydrate, 41B, 940... 

Cl2HsoCl6CoCrNi20s, (+) Tris(ethylenediamine)cobalt(III) (-) tris-(ethylenediamine)chromium(III) chloride hydrate, 42B, 729 Cl2H6oCl6CrNi20gRh, (+) Tris(ethylenediamine)chromium(III) (+)-tris-(ethylenediamine)rhodium(III) chloride hydrate, 42B, 729 Cl2H60CI7CO2N12NaOg, Sodium D-tris(ethylenediamine)cobalt(III) chloride hexahydrate, 19, 539 21, 547 Cl2H60CI7CO2N12NaOfi, Sodium L-tris-(ethylenediamine)cobalt(111) chloride hexahydrate, 19, 539... 

Chromium(IH) chloride, chromic chloride, CrClj. Violet solid (Cr plus CI2, hydrate plus SOCI2) only soluble in water in presence of Cr. Forms many complexes including the hydrates [Cr(H20)6]Cl3 - violet, [Cr(H20)jCl]Cl2,H20 - green, [Cr(H20)4Cl2]Cl,2H20 - green. 

Chromium(IJ) chloride, chromous chloride, CrCl2- White solid (Cr plus HCl gas) dissolving to give a blue solution. Forms hydrates, widely used as a reducing agent. 

Sulphur dichloride oxide (thionyl chloride) on the hydrated chloride can also be used to produce the anhydrous chloride in certain cases, for example copper(II) chloride and chromium(III) chloride ... 

Hydrated chromium(III) sulphate exhibits different colours and different forms from which varying amounts of sulphate ion can be precipitated by barium chloride, due to the formation of sulphato-complexes. Chromium(III) sulphate can form alums. 

Ammonia forms a great variety of addition or coordination compounds (qv), also called ammoniates, ia analogy with hydrates. Thus CaCl2 bNH and CuSO TNH are comparable to CaCl2 6H20 and CuSO 4H20, respectively, and, when regarded as coordination compounds, are called ammines and written as complexes, eg, [Cu(NH2)4]S04. The solubiHty ia water of such compounds is often quite different from the solubiHty of the parent salts. For example, silver chloride, AgQ., is almost iasoluble ia water, whereas [Ag(NH2)2]Cl is readily soluble. Thus silver chloride dissolves ia aqueous ammonia. Similar reactions take place with other water iasoluble silver and copper salts. Many ammines can be obtained ia a crystalline form, particularly those of cobalt, chromium, and platinum. 

Ghromium(II) Compounds. The Cr(II) salts of nonoxidizing mineral acids are prepared by the dissolution of pure electrolytic chromium metal ia a deoxygenated solution of the acid. It is also possible to prepare the simple hydrated salts by reduction of oxygen-free, aqueous Cr(III) solutions using Zn or Zn amalgam, or electrolyticaHy (2,7,12). These methods yield a solution of the blue Cr(H2 0)g cation. The isolated salts are hydrates that are isomorphous with and compounds. Examples are chromous sulfate heptahydrate [7789-05-17, CrSO 7H20, chromous chloride hexahydrate... 

With Acyl Halides, Hydrogen Halides, and Metallic Halides. Ethylene oxide reacts with acetyl chloride at slightly elevated temperatures in the presence of hydrogen chloride to give the acetate of ethylene chlorohydrin (70). Hydrogen haUdes react to form the corresponding halohydrins (71). Aqueous solutions of ethylene oxide and a metallic haUde can result in the precipitation of the metal hydroxide (72,73). The haUdes of aluminum, chromium, iron, thorium, and zinc in dilute solution react with ethylene oxide to form sols or gels of the metal oxide hydrates and ethylene halohydrin (74). 

Chromium, tetraaquadichloro-chloride dihydrate hydrate isomerism, 1, 183 Chromium, tetrabromo-solvated, 3, 758 synthesis, 3, 763 Chromium, tetrachloro-antiferromagnetic, 3, 761 ferromagnetic magnetic properties, 3,7559 optical properties, 3,759 structure, 3,759 solvated, 3. 758 synthesis. 3, 759 Chromium, tetrachlorooxy-tetraphenylarsenate stereochemistry, 1,44 Chromium, tetrahalo-, 3,889 Chromium, tetrakis(dioxygen)-stereochemistry, 1,94 Chromium, triamminediperoxy-structure. 1, 78 Chromium, tricyanodiperoxy-structure, 1, 78 Chromium, trifluoro-electronic spectra, 3, 757 magnetic properties, 3, 757 structures, 3, 757 synthesis, 3, 756 Chromium, trihalo-clcctronic spectra, 3, 764 magnetic properties, 3, 764 structure, 3, 764 synthesis, 3, 764 Chromium, tris(acetylacetone)-structure. 1, 65 Chromium, tris(bipyridyl)-... 

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