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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+. [10] 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 ...
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 ...
water 1 liter, 30 - 40 C, 30 - 100A/dm2, duration 10 - 20 min, 6 - 9v, distance object anode 30 - 100mm. A variant of this procedure is the so-called chromium oxide procedure (250 - 300 gr of chromium anhydride, 1 - 5 gr of potassium ferrocyanide, 20 - 100 A/dm2, max. 25 C) [35]
It is obtained on a vast scale by roasting chromium ores in air in the presence of sodium carbonate: 2Cr 2 O 3 + 4 Na 2 CO 3 + 3 O 2 → 4 Na 2 CrO 4 + 4 CO 2. This process converts the chromium into a water-extractable form, leaving behind iron oxides.
Chromium(II) ion in aqueous solution. Most aquo complexes are mono-nuclear, with the general formula [M(H 2 O) 6] n+, with n = 2 or 3; they have an octahedral structure. The water molecules function as Lewis bases, donating a pair of electrons to the metal ion and forming a dative covalent bond with it. Typical examples are listed in the ...
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
Chromium(II) oxide (CrO) is an inorganic compound composed of chromium and oxygen. [1] It is a black powder that crystallises in the rock salt structure. [2] Hypophosphites may reduce chromium(III) oxide to chromium(II) oxide: H 3 PO 2 + 2 Cr 2 O 3 → 4 CrO + H 3 PO 4. It is readily oxidized by the atmosphere. CrO is basic, while CrO 3 is ...
Chromium trioxide (also known as chromium(VI) oxide or chromic anhydride) is an inorganic compound with the formula CrO 3. It is the acidic anhydride of chromic acid, and is sometimes marketed under the same name. [6] This compound is a dark-purple solid under anhydrous conditions and bright orange when wet. The substance dissolves in water ...