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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 is a chemical element; it has symbol Cr and atomic number 24. ... The name of the element is derived from the Greek word χρῶμα, ... (PbCrO 4 ·Pb(OH) 2 ...
When a salt of a metal ion, with the generic formula MX n, is dissolved in water, it will dissociate into a cation and anions. [citation needed]+ + (aq) signifies that the ion is aquated, with cations having a chemical formula [M(H 2 O) p] q+ and anions whose state of aquation is generally unknown.
2 CrO 2− 4 + 2 H + ⇌ Cr 2 O 2− 7 + H 2 O The predominance diagram shows that the position of the equilibrium depends on both pH and the analytical concentration of chromium. [ notes 1 ] The chromate ion is the predominant species in alkaline solutions, but dichromate can become the predominant ion in acidic solutions.
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+
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...
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 ...
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: [7] Na 2 Cr 2 O 7 + S → Na 2 SO 4 + Cr 2 O 3. The oxide is also formed by the decomposition of chromium salts such as chromium nitrate, or by the exothermic ...