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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 are rare, but do nevertheless occasionally exist.
Further condensation reactions can occur in strongly acidic solution with the formation of trichromates, Cr 3 O 2− 10, and tetrachromates, Cr 4 O 2− 13. [2] All polyoxyanions of chromium(VI) have structures made up of tetrahedral CrO 4 units sharing corners. [3] The hydrogen chromate ion, HCrO 4 −, is a weak acid: HCrO − 4 ⇌ CrO 2−
The Parisians Pannetier and Binet first prepared the transparent hydrated form of Cr 2 O 3 in 1838 via a secret process, sold as a pigment. [7] It is derived from the mineral chromite, (Fe,Mg)Cr 2 O 4. The conversion of chromite to chromia proceeds via Na 2 Cr 2 O 7, which is reduced with sulfur at high temperatures: [8] Na 2 Cr 2 O 7 + S → ...
Names IUPAC name. iron(III) chromate. ... 4 Fe 2 O 3 + 6 Cr 2 O 3 + 9 O 2 → 4 Fe 2 (CrO 4) 3. References This page was last edited on 24 December 2024, at 16:33 ...
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. Typically calcium carbonate is included in the mixture to improve oxygen access and to keep silicon and aluminium impurities in an insoluble form. The process temperature is typically around ...
Although most compounds are referred to by their IUPAC systematic names ... (III) nitrate – Cr(NO 3) 3; Chromium(III) oxide – Cr 2 O 3;
Cr(ClO 4) 3 will react with NH 3 in suitable conditions to form an orange hexammine complex Cr(ClO 4) 3 ·6NH 3. [4] Other compounds with the general formula Cr(ClO 4) 3 (NH 3) x are also known. When x = 3, this compound is red, when x = 4 or 5, it is orange. [5] The hexammine complex will explode. [5]
It is a red-brown paramagnetic solid. It is the potassium salt of tetraperoxochromate(V), one of the few examples of chromium in the +5 oxidation state and one of the rare examples of a complex stabilized only by peroxide ligands. [2] This compound is used as a source of singlet oxygen. [1]