Violet chromic chloride

Hexammino-ehromic Chloride, [Cr(NH3)6]Cl3.H20, is produced by the addition of concentrated hydrochloric acid to a solution of the nitrate, or, better, by the decomposition of the mercury double salt, [Cr(NH3)6]Cl3.(HgCl2), with hydrogen sulphide, when a purer chloride is obtained.3 It is formed as one of the products of the action of liquid ammonia on anhydrous violet chromic chloride.4... 

An interesting form of isomerism, dependent on the formation of such cations, is exhibited by chromic salts, which usually exist in at least two modifications, the one green and the other violet or dark blue. In both varieties the chromium is in the same state of oxidation, but the non-metallic radicle, while apparently freely ionised in a violet solution, is only partly active in the green. Thus the chlorine in violet chromic chloride, CrQj.eHjO, is completely precipitated by the addition of a soluble silver salt, but in the ordinary green variety only one-third of See Vol. X. of this series. 

K. Hopfgartner found the transport numbers for violet chromic chloride in 1-00, 0-32, and 0-075 eq. soln. to be respectively 0 318, 0-357, and 0-414, or extrapolating to zero concentration, 0-446. The mobilities of the ions are respectively 53, 49-5, and 46-3. These results indicate that the chromic ion is probably surrounded by a fairly large water sheath. N. Bjerrum found the constant of hydrolysis, as in the case of the dark green salt, and the percentage degree of hydrolysis, to be ... 

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. 

The anhydrous chromium (III) chloride may be obtained by heating the hydrated salt CrCls 6H2O with SOCI2 and subliming the product in a stream of chlorine at 600°C. Alternatively, the red-violet anhydrous chloride can be obtained by passing chlorine gas over a mixture of chromic oxide and carbon ... 

Dihydroxo-diaquo-diammino-chromic Chloride, [Cr(NH3), (H20)2(OH)2]Cl, is formed by the addition of ammonia or pyridine to an aqueous solution of tetraquo-diammino-chloride, or saturating an aqueous acetic acid solution with rubidium chloride. It forms light red violet crystals which are insoluble in water. The iodide is obtained from the bromide on addition of potassium iodide to a dilute acetic acid solution of the salt as a light red violet precipitate. The thiocyanate, [Cr(NH3)2(H20)2(OH)2]SCN, is amorphous, and is prepared from the bromide by dissolving in aqueous acetic acid and adding potassium thiocyanate. 

The bromide, [Cr3 en4(0H)2]Cl4.2H20, is stated by Dubsky to contain 2 molecules of water in the molecule, and by Pfeiffer 2-5 molecules. This salt is prepared by treating a dilute aqueous solution of cis-dibis-aquo-diethylenediamino-chromic bromide with pyridine.3 It separates in lustrous bluish-violet crystals, which are soluble in water with neutral reaction. Halogen acids transform it into the m-diacido-salt for example, with hydrochloric acid it forms dichloro-diethylenediamino-chromic chloride, [Cr en2Cl2]Cl.H20. Other salts of the series may be obtained from the bromide. 

PROP Red-violet flaky crystals. Mp 1152°, bp 1300° (subl). Insol in cold H2O sltly sol in hot H2O. IDLH 25 mg/m [as Cr(III)]. SYNS CHROMIC CHLORIDE CHROMIUM(III) CHLORIDE (1 3) CHROMIUM CHLORIDE, anhydrous CHROMUM TRICHLORIDE C.I. 77295 PURATRON-IC CHROMIUM CHLORIDE TRICHLOROCHROMIUM... 

Chromic chloride, C l3 6H20, forms several kinds of crystals, varying in color from violet to green, the solutions of which have similar colors. These diflEerent colors are due to the formation of stable complex ions (Fig. 25-3) ... 

Stannic Chromate.— When stannic chloride is added to a solution of potassium chromate a yellow precipitate is formed, while the liquid becomes orange-yellow, free chromic acid being liberated. The precipitate, when dried, becomes brownish yellow and translucent, and on heating changes into violet chromic stannate. ... 

Double Gompounds with the Halides of Phosphorus.— When chromic chloride or chromyl chloride is heated with excess of phosphorus pentachloride in a sealed tube, a violet crystalline compound, having the composition PClj.CrClg, results. ... 

Chromium Chlorantimonate or Chromium Metantimoni-chloride, Cr(SbCle)3.13H20, has been obtained as grey-violet, flat, hygroscopic needles by the action of antimony pentachloride on chromic chloride. The salt may be formulated according to Werner s... 

This acid is produced by the energetic action of fuming sulphuric acid on amidoazobenzene. It forms shimmering violet crystals resembling chromic chloride, which on drying disintegrate. 

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