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The Pourbaix diagram for chromium in pure water, perchloric acid, or sodium hydroxide [1] [2] Chromium compounds are compounds containing the element chromium (Cr). Chromium is a member of group 6 of the transition metals. The +3 and +6 states occur most commonly within chromium compounds, followed by +2; charges of +1, +4 and +5 for chromium ...
Chromium(III) oxide is amphoteric. Although insoluble in water, it reacts with acid to produce salts of hydrated chromium ions such as [Cr(H 2 O) 6] 3+. [11] It is also attacked by concentrated alkali to yield salts of [Cr(OH) 6] 3−. When heated with finely divided carbon or aluminium, it is reduced to chromium metal: Cr 2 O 3 + 2 Al → 2 Cr ...
Oxidation states are typically represented by integers which may be positive, zero, or negative. In some cases, the average oxidation state of an element is a fraction, such as 8 / 3 for iron in magnetite Fe 3 O 4 . The highest known oxidation state is reported to be +9, displayed by iridium in the tetroxoiridium(IX) cation (IrO + 4). [1]
Chromium trioxide decomposes above 197 °C, liberating oxygen and eventually giving Cr 2 O 3: 4 CrO 3 → 2 Cr 2 O 3 + 3 O 2 It is used in organic synthesis as an oxidant, often as a solution in acetic acid , [ 9 ] or acetone in the case of the Jones oxidation .
The oxidation states are also maintained in articles of the elements (of course), and systematically in the table {{Infobox element/symbol-to-oxidation-state}} See also [ edit ]
Chromium hexacarbonyl (IUPAC name: hexacarbonylchromium) is a chromium(0) organometallic compound with the formula Cr 6. It is a homoleptic complex , which means that all the ligands are identical. It is a colorless crystalline air-stable solid, with a high vapor pressure .
Acicular chromium dioxide was first synthesized in 1956 by Norman L. Cox, a chemist at E.I. DuPont, by decomposing chromium trioxide in the presence of water at a temperature of 800 K (527 °C; 980 °F) and a pressure of 200 MPa. The balanced equation for the hydrothermal synthesis is: 3 CrO 3 + Cr 2 O 3 → 5 CrO 2 + O 2
Chromium oxide may refer to: Chromium(II) oxide, CrO; Chromium(III) oxide, Cr 2 O 3; Chromium dioxide (chromium(IV) oxide), CrO 2, which includes the hypothetical compound chromium(II) chromate; Chromium trioxide (chromium(VI) oxide), CrO 3; Chromium(VI) oxide peroxide, CrO 5; Mixed valence species, such as Cr 8 O 21