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| Vanadium(III)-ammonium sulfate | |
|---|---|
| Names: | ammonium-vanadium(III) sulfate monoammonium-vanadium(III) sulfate vanadium-ammonium alum vanadium alum |
| Formula: | NH4V(SO4)2 (anhydrous) NH4V(SO4)2 · 12H2O (dodecahydrate) |
| Molar mass: | 261.103 g/mol (anhydrous) 477.281 g/mol (dodecahydrate) |
| Density: | 1.69 g/cm3 (dodecahydrate) |
| Crystal system: | cubic (dodecahydrate) α=90°, β=90°, γ=90° |
| Shapes: |
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| Color: | dark-red dark-violet black |
| Melting point: | 45 °C318.15 K <br />113 °F <br />572.67 °R <br /> (dodecahydrate) |
| Decomposition point: | 300 °C573.15 K <br />572 °F <br />1,031.67 °R <br /> (anhydrous) |
| Stability: | erodes (dodecahydrate) hygroscopic (anhydrous) |
| Hardness: | strong |
| Toxicity: | highly toxic |
Description
Inorganic compound, double salt of transitional metal vanadium, ammonium ion and inorganic sulfuric acid. From water solutions crystallizes as dodecahydrate.
Precursors
Reaction between vanadium and ammonium sulfates
Chemical equation:
100.00g of vanadium(III)-ammonium sulfate dodecahydrate а 40.86g of vanadium(III) sulfate and 13.84g of ammonium sulfate is required.Dissolve compounds in hot water apart and then mix solutions into one container with intense stirring. Cooling or evaporation of a solution will cause double salt crystallyzation.
Reaction between vanadyl sulfate, sulfuric acid and zinc with addition of ammonium sulfate
Chemical equation:
100.00g of vanadium(III)-ammonium sulfate dodecahydrate а 45.48g of vanadyl sulfate trihydrate, 55.54g of 37% sulfuric acid, 6.85g of zinc and 13.84g of ammonium sulfate is required.Add to the flask with sulfuric acid a ammonium sulfate solution with stirring.Add hot acid solution to the flask, then add vanadyl sulfate and zinc pieces, shavings or powder and stir it until gas emission will stop.
Reaction between vanadyl sulfate, tin(II) chloride and hydrochloric acid with addition of ammonium sulfate
Chemical equation:
100.00g of vanadium(III)-ammonium sulfate dodecahydrate а 45.48g of vanadyl sulfate trihydrate, 40.21g of 38% hydrochloric acid, 23.64g of chloride tin dihydrate and 27.69g of ammonium sulfate is required.Add to the flask with hydrochloric acid a ammonium and vanadyl sulfates solution with stirring.Add hot acid to the flask, then add small parts of tin compound with stirring until it will totally dissolve .
Reaction between ammonium metavanadate, sulfuric acid and any reducing agentsuch as ethanol, isopropanol, oxalic acid, formic acid or glucose
Chemical equation:
100.00g of vanadium(III)-ammonium sulfate dodecahydrate а 24.51g of ammonium metavanadate, 9.65g of ethanol or 12.59g of isopropanol or 18.86g of oxalic acid or 3.70g of 85% formic acid or 3.15g of glucose and 111.08g of 37% sulfuric acid is required.Add to the flask saturated solution of sulfuric acid and ammonium metavanadate and then add small parts of hot reducing agent solution with heating and stirring. Emission of large amount of gas will begin.Attention, exuding gas irritates eyes and lungs! The synthesis should be carried out only in a fume hood or outdoors!
Reaction between pure vanadium, ammonium nitrate and sulfuric acid
Chemical equation:
100.00g of vanadium(III)-ammonium sulfate dodecahydrate а 10.67g of vanadium, 16.77g of ammonium nitrate and 111.08g of 37% sulfuric acid is required.Add to the flask with sulfuric acid a nitrate ammonium solution with stirring.Add acid to the flask, then add small parts of vanadium compound with stirring until it will totally dissolve . Attention, exuding nitric oxide irritates eyes and lungs! The synthesis should be carried out only in a fume hood or outdoors! After reaction will stop, filter the solution and use it for crystal growing.
Reaction between chloride and ammonium sulfate
Chemical equation:
100.00g of vanadium(III)-ammonium sulfate dodecahydrate а 55.60g of vanadium(III) chloride hexahydrate and 55.37g of ammonium sulfate is required.Dissolve compounds in hot water apart and then mix solutions into one container with intense stirring. Cooling or evaporation of a solution will cause double salt crystallyzation. Filter precipitate and wash it wish small amount of ethanol or acetone, then filter the solution and use it for crystal growing.
Reaction between vanadium(III) sulfate and nitrate or ammonium chloride
Chemical equation:
100.00g of vanadium(III)-ammonium sulfate dodecahydrate а 54.48g of vanadium(III) sulfate and 16.77g of ammonium nitrate or 11.21g of ammonium chloride is required.Dissolve compounds in hot water apart and then mix solutions into one container with intense stirring. Cooling or evaporation of a solution will cause double salt crystallyzation. Filter precipitate and wash it wish small amount of ethanol, then filter the solution and use it for crystal growing.
Influence of impurities
Addition of borax has no affect on crystal shape, as it does with ammonium alum.
Notes
Due to crystal erosion in the air, they are usually coated with a layer of ammonium alum. Alums are isomorphous between each other, so they are not dissolving in saturated solution of other alums.
Also, you can combine alums in one solution, getting crystals of other shades.
Storage conditions
For crystal storing use hermetic vessel with small amount of saturated solution at the bottom or place wadding moistened with such solution. You can use such alternatives as vessel with vaseline or vegetable oil, organic non-hygroscopic solvent (kerosene, benzine or paraffin). Also you can use acrylate polymer or another kinds of solidifying plastic.
Solubility
Gallery
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Compound was prepared by reducing vanadyl sulfate with tin(II) chlorideVanadium(III)-ammonium sulfate, Vladimir Semikin, VKontakteVKontakte
Sources
| Vanadium compounds | |
|---|---|
|
Vanadium(II)-ammonium sulfate ((NH4)2V(SO4)2) • Vanadium(III)-ammonium sulfate (NH4V(SO4)2) |