Chromic oxide, hydrated

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... 

Chromium hydroxide green CAS 12001-99-9 EINECS/ELINCS 215-160-9 Synonyms Chromic oxide hydrated Chromium oxide hydrate Cl 77289 Dichromium trioxide Guignet s green... 

Methyl ketones are important intermediates for the synthesis of methyl alkyl carbinols, annulation reagents, and cyclic compounds. A common synthetic method for the preparation of methyl ketones is the alkylation of acetone derivatives, but the method suffers limitations such as low yields and lack of regioselectivity. Preparation of methyl ketones from olefins and acetylenes using mercury compounds is a better method. For example, hydration of terminal acetylenes using HgSO gives methyl ketones cleanly. Oxymercuration of 1-olefins and subsequent oxidation with chromic oxide is... 

Chromoxyd, n. chromium oxide, specif, chromic oxide, chromium(III) oxide. -farbe, /. chrome oxide color, -hydrat, n. chromium hydroxide, specif, chromic hydroxide, chro-mium(III) hydroxide, -natron, n. sodium chromite. -salz, n. chromic salt, chro-mium(III) oxide-... 

Chromic Perchlorate. Cr(C104)3, mw 350.30, OB to CrO HCI +28.5% only the hexahydrate has been prepd as blue-green delq crysts, mp 94° (Refs 1, 5 6) CA Registry No 13537-21-8 Preparation. By dissolving hydrated chromic oxide in 20% perchloric ac followed by-evapn of the soln (Ref 4)... 

Fio. 16. Spectra of chromic oxide and of chromic ion in a hydrated salt, in anion and in cation complexes. 

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 ... 

Formula Cr(0H)3 3H20 MW 157.06 occurs only as hydrates Synonyms chromic hydroxide chromic oxide hydrous chromic oxide gel chromium hydrate chromic hydrate. 

The other abrasive agents used are tin oxide, chromic oxide, sand, carbides (silicon carbide and boron carbide), zirconium silicate, zinc oxide, garnet, rouge (fine red powder of iron oxide), kieselgurh, tripoli, magnesium oxide, hydrated silica etc. 

Oxidation of quinazoline with various oxidizing agents, e.g. hydrogen peroxide, chromic oxide, peracetic acid, or monoperoxyphthalic acid, affords quinazolin-4(3//)-one in high yield. The reactive species is in fact the hydrated cation which is formed from quinazoline in the presence of even a trace of water and which is readily oxidized to the respective oxo compound (cf. p 161). 2-Substituted quinazolines react similarly, whereas when a substituent is present at C4, the hydrated cation is not readily formed and the more sensitive substituent is oxidized. 

With alkali hydroxide a solution of chromous chloride yields a yellowish-brown precipitate which absorbs oxygen, forming a hydrated chromo-chromic oxide, Cr304.H20. 

Chromo-chromic Oxides.—Two hydrated oxides, CrjO. HgO and... 

More recent investigations have shown that when strongly heated chromic oxide (which, contrary to common statements, is not entirely insoluble in acids) is dissolved in hot concentrated nitric acid of density 1-4, the hydrate Cr2(N03)6.15H20 crystallises on cooling. The dark brown crystals are prismatic ... 

Chromic Hydroxide. Chromium hydroxide, chromic oxide gel chromic oxide, hydrous. CrH3Oj mol wt 103.03. Cr 50.48%. H 2-93%, O 46.59%. Cr(OH)j. Occurs only as hydrates. Prepn Ruthroff, Inorg. Syn. 2, 190 (1946) Hein, Herzog in Handbook of Preparative Inorganic Chemistry vol. 2, G- Brauer, Ed, (Academic Press, New York, 2nd ed- 1965) pp 1345-1346. 

Chromium can occur in water either in the oxidation state III or VI. Cr(III) possesses significant complex-forming properties. The Cr(VI) forms are stable in aerobic media. In anaerobic media Cr(VI) can be reduced to Cr(III), chromium is eliminated from the liquid phase in the form of low soluble hydrated chromic oxide. 

Analyses of the hydrates of chromic oxide vary very much. According to... 

R. Fricke and 0. Windhausen attributed the ageing to an increase in the size of the particles, and showed that it is not due to dehydration, or to the development of a microcrystalline structure. R. Fricke and co-workers observed no evidence of a crystalfine structure in the ageing of hydrated chromic oxide. 

A. Recoura gave for the heat of neutralization of hydrated chromic oxide with hydrochloric acid Cr(OH)3=6-865 Cals. E. Petersen, with hydrofluoric acid. 

The colloidal soln. of hydrated chromic oxide prepared as just indicated was shown by W. Biltz, and W. Herz to be a positive h drosol because it migrates to the cathode under the influence of an electrical stress. On the other hand, the... 

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