Vanadium sulfate

The compound can be prepared from 2,4,6-trinitrophenol (picric acid [88-89-1]) by reduction with sodium hydrosulfide (163), with ammonia —hydrogen sulfide followed by acetic acid neutralization of the ammonium salt (164), with ethanolic hydrazine and copper (165), or electrolyticaHy with vanadium sulfate in alcoholic sulfuric acid (159). Heating 4,6-dinitro-2-benzamidophenol in concentrated HQ. at 140°C also yields picramic acid (166). 

Vanadium Sulfates. Sulfate solutions derived from sulfuric acid leaching of vanadium ores are industrially important in the recovery of vanadium from its raw materials. Vanadium in quadrivalent form may be solvent-extracted from leach solutions as the oxycation complex (VO) ". Alternatively, the vanadium can be oxidized to the pentavalent form and solvent-extracted as an oxyanion, eg, (V O ) . Pentavalent vanadium does not form simple sulfate salts. 

Vanadin-saure, /. vanadic acid, -saurean-hydrid, n. vanadic anhydride, vanadium pentoxide, vanadium(V) oxide, V2O6. -stahl, m. vanadium steel, -stickstoff, m. vanadium nitride, -sulfat, n. vanadium sulfate, -ver-bindung, /. vanadium compoimd. 

Vanadium sulfate (VOSO ) acts as a catalyst as well as a reducing agent. It is used to color glass and ceramics and as a mordant (fixing dyes to textiles). 

An indirect vanadometric method of assay for camphor was developed. The method involves the formation of 2, -dinitrophenylhydrazone of camphor. The nitro groups in the hydrazone are then reduced to amines by treatment with vanadium sulfate (VSOl ) and the excess of the reagent is back titrated with sodium dichromate (NapCrpO-y). The entire procedure is carried out in a modified separatory funnel into which standard vanadate, 6tJ and zinc amalgam... 

A solution of 8.0 g (31 mmol) of VS04-6H20 is prepared in 25 mL of water at 0°C. Separately, a solution of 16.6 g (68 mmol) of sodium saccharinate dihydrate is made in 27 mL of water. The latter solution is cooled to 10-15 °C and is added to the vanadium sulfate. Upon mixing, the color changes to red. To the reaction mixture is added 20 mL of chilled 95% ethanol. After 24h at 0°C a crop of crystals is obtained. The red solid is thoroughly washed with five portions of 20 mL of cooled water and is dried under vacuum for 2h. Yield 4.3 g (26%). 

Divanadium(V) oxide catalysts are currently almost exclusively used. They are fused salts, which in a cold state consist essentially of vanadium sulfate and potassium disulfate, applied to a porous support (kieselguhr or diatomaceous earth). The change in valency state between and V -ions is probably a critical. step in the catalysis. The lowest operating temperature of this catalyst is generally ca. 420 to 440°C. 

Because vanadium ions exist in four different oxidation states (as V2+, V3+, V02+ and V02+) in aqueous solution, redox couples can be formed by all vanadium ions. The emf of a vanadium redox battery is 1.4 V and the electrode kinetics are higher than those of the Fe-Cr battery. Also, the energy density of the battery can be increased due to the high solubility of vanadium salts.257 In the battery, vanadium sulfate solution is used,... 

Frank P, Hedman B, Hodgson (1999) Sulfur allocation and vanadium-sulfate interactions in whole blood cells from the tunicate Ascidia ceratodes, investigated using X-ray absorption spectroscopy. Inorg Chem 38 260-270... 

The electrolyte used for the electrodeposition [37, 58] was a 1M aqueous vanadium sulfate oxide hydrate solution containing 50 %wt ethanol with a pH of 1.6. A standard... 

The electrolyte is a mixture of 2 mole/L vanadium sulfate and 20 wt% sulfuric acid. 

The electrolytes in the positive and negative electrode compartments of VRBs are different valence states of vanadium sulfate. Both solutions are 2 M in concentration and contain sulfuric acid as a supporting electrolyte. The electrode reactions occur in solution, with the reaction at the negative electrode in discharge being ... 

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