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VO 2+, often in an ionic pairing with sodium (NaH 2 VO 4), is the second most abundant transition metal in seawater, with its concentration only being exceeded by molybdenum. [4] In the ocean the average concentration is 30 nM. Some mineral water springs also contain the ion in high concentrations.
From left: [V(H 2 O) 6] 2+ (lilac), [V(H 2 O) 6] 3+ (green), [VO(H 2 O) 5] 2+ (blue) and [VO(H 2 O) 5] 3+ (yellow).. Vanadium compounds are compounds formed by the element vanadium (V). The chemistry of vanadium is noteworthy for the accessibility of the four adjacent oxidation states 2–5, whereas the chemistry of the other group 5 elements, niobium and tantalum, are somewhat more limited to ...
Vanadium(IV) oxide or vanadium dioxide is an inorganic compound with the formula VO 2.It is a dark blue solid. Vanadium(IV) dioxide is amphoteric, dissolving in non-oxidising acids to give the blue vanadyl ion, [VO] 2+ and in alkali to give the brown [V 4 O 9] 2− ion, or at high pH [VO 4] 4−. [4]
Phases with the general formula V n O 2n−1 exist between VO 2 and V 2 O 3. [1] Called Magnéli phases for Arne Magnéli, [2] they are examples of crystallographic shear compounds based on the rutile structure. [1] Examples of Magnéli phases include V 4 O 7, V 5 O 9, V 6 O 11, V 7 O 13 and V 8 O 15. V 3 O 5 appears as the mineral oxyvanite ...
The oxidation state of oxygen is −2 in almost all known compounds of oxygen. The oxidation state −1 is found in a few compounds such as peroxides . Compounds containing oxygen in other oxidation states are very uncommon: − 1 ⁄ 2 ( superoxides ), − 1 ⁄ 3 ( ozonides ), 0 (elemental, hypofluorous acid ), + 1 ⁄ 2 ( dioxygenyl ), +1 ...
Conventionally this ion is represented with a single double bond, however this is a resonance form as the ion is a regular tetrahedron with four equivalent oxygen atoms. Additionally a range of polyoxovanadate ions exist which include discrete ions and "infinite" polymeric ions. [ 2 ]
The dichromate ion, Cr 2 O 2− 7, is predominant in more concentrated solutions, except at high pH. The species H 2 CrO 4 and HCr 2 O − 7 are not shown as they are formed only at very low pH. Predominance diagrams can become very complicated when many polymeric species can be formed, [ 10 ] such as in vanadates , molybdates , and tungstates .
The reaction is performed between 400 and 620 °C; below 400 °C the V 2 O 5 is inactive as a catalyst, and above 620 °C it begins to break down. Since it is known that V 2 O 5 can be reduced to VO 2 by SO 2, one likely catalytic cycle is as follows: SO 2 + V 2 O 5 → SO 3 + 2VO 2. followed by 2VO 2 +½O 2 → V 2 O 5