BOD513
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Transition Metal Bisulfates
Hey guys,
Does anyone have any experience making the bisulfate form of any metals other than sodium or potassium, or even know if these would be stable? I have
seen a few mentions of using them as catalysts, but the only method of synthesis they list is mixing conc. sulfuric acid with the metal chlorides and
removing the hcl under reduced pressure- I don't have a vacuum setup, and have tried using a stoichiometric amount of conc. sulfuric acid with
magnesium sulfate, titanium dioxide, and zinc and aluminum metal. In the case of the metals, I assume the low ionic conductivity limits the rate of
oxidation, but I can't see why the sulfates or acid-soluble oxides wouldn't react. I'm wondering if the bisulfates just preferentially form the metal
sulfate and sulfuric acid. Would a hydroxide be a better choice? Do I have no option but to dissolve everything in water and try to evaporate it off?
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Meltonium
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Do you have any specific transition metal bisulfate you need? Also what are you using it to catalyze?
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DraconicAcid
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I don't think they form stable solids, but you can form them in solution just by adding the metal sulphate and sulphuric acid in a 1:1 ratio (that's
sulphate:acid). Or a metal carbonate/oxide with excess sulphuric acid.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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chornedsnorkack
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Apparently many of them do not form bisulphates.
From Non-Aqueous Solvents in Inorganic Chemistry: The Commonwealth and ...
By A. K. Holliday,A. G. Massey
page 50:
Ba and Mg, for example, do give bisulphates - as well as crystal solvates with sulphuric acid. Whereas Al and Sn are quoted as poorly soluble and
nonsolvated in strong sulphuric acid.
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BOD513
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Meltonium, I don't have any particular application in mind- I just thought they might be interesting compounds and my interest was piqued by the lack
of information out there. I thought they might behave as Lewis acids similar to the transition metal chlorides, without the annoying tendency to
hydrolyze.
Chornedsnorkack, that's one of the reasons I found them cool- I would have imagined that Ba would yield a bisulfate only transiently because of the
extremely low solubility of barium sulfate precipitating it out of the solution.
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chornedsnorkack
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Quote: Originally posted by BOD513  |
Chornedsnorkack, that's one of the reasons I found them cool- I would have imagined that Ba would yield a bisulfate only transiently because of the
extremely low solubility of barium sulfate precipitating it out of the solution. |
Indeed. Barium sulphate is a substance whose solubility is low in water, but increases in concentrated sulphuric acid. Whereas aluminum sulphate
dissolves well in water, but precipitates out of concentrated acid.
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