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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.
Chromium(III) hydroxide (Cr(OH) 3) is amphoteric, dissolving in acidic solutions to form [Cr(H 2 O) 6] 3+, and in basic solutions to form [Cr(OH) 6] 3−. It is dehydrated by heating to form the green chromium(III) oxide (Cr 2 O 3), a stable oxide with a crystal structure identical to that of corundum. [21]
The number of open chain stereoisomers for an aldose monosaccharide is larger by one than that of a ketose monosaccharide of the same length. Every ketose will have 2 (n−3) stereoisomers where n > 2 is the number of carbons. Every aldose will have 2 (n−2) stereoisomers where n > 2 is the number of carbons. These are also referred to as ...
Chromium(III) hydroxide is a gelatinous green inorganic compound with the chemical formula Cr(OH) 3. It is a polymer with an undefined structure and low solubility. It is amphoteric, dissolving in both strong alkalis and strong acids. [2] In alkali: Cr(OH) 3 + OH − → CrO − 2 + 2 H 2 O In acid: Cr(OH) 3 (OH 2) 3 + 3 H + → Cr(OH 2) 6 3+
The Cr 2 (OAc) 4 (H 2 O) 2 molecule contains two atoms of chromium, two ligated molecules of water, and four acetate bridging ligands.The coordination environment around each chromium atom consists of four oxygen atoms (one from each acetate ligand) in a square, one water molecule (in an axial position), and the other chromium atom (opposite the water molecule), giving each chromium centre an ...
Cr 2 O 3 has the corundum structure, consisting of a hexagonal close packed array of oxide anions with 2 ⁄ 3 of the octahedral holes occupied by chromium. Similar to corundum, Cr 2 O 3 is a hard, brittle material (Mohs hardness 8 to 8.5). [4] It is antiferromagnetic up to 307 K, the Néel temperature. [5] [6] It is not readily attacked by acids.
In organic chemistry, a hydrate is a compound formed by the hydration, i.e. "Addition of water or of the elements of water (i.e. H and OH) to a molecular entity". [5] For example: ethanol , CH 3 −CH 2 −OH , is the product of the hydration reaction of ethene , CH 2 =CH 2 , formed by the addition of H to one C and OH to the other C, and so ...
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 ...