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woelen
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Mn(3+) is stable at very low pH. I made this myself and could keep it around in a test tube for several days. After that I used it for further
experiments.
V(2+) might be unstable. I can imagine that it reduces water and that hydrogen is formed.
For many anions, sulfate is suitable as well. Sulfate does not coordinate to copper(II), cobalt(II), nickel(II). It does coordinate to Cr(3+) though.
With iron(III) I never tried, but I expect that in dilute sulphuric acid the iron(III) ion also looks nearly colorless.
Dilute nitrate (less than 1 M) certainly does not tend to form NO2 when no suitable reductor is present. Dilute solutions of nitrates of nearly all
metal ions, even the somewhat reducing ones, are stable. Even better indeed are perchlorates. These are very stable in aqueous solution, even more so
than sulfate. Only at high temperatures or in near anhydrous situations the perchlorates and perchloric acid become strongly oxidizing.
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chornedsnorkack
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Quote: Originally posted by woelen  | Mn(3+) is stable at very low pH. I made this myself and could keep it around in a test tube for several days. After that I used it for further
experiments.
V(2+) might be unstable. I can imagine that it reduces water and that hydrogen is formed.
For many anions, sulfate is suitable as well. Sulfate does not coordinate to copper(II), cobalt(II), nickel(II). It does coordinate to Cr(3+) though.
With iron(III) I never tried, but I expect that in dilute sulphuric acid the iron(III) ion also looks nearly colorless.
Dilute nitrate (less than 1 M) certainly does not tend to form NO2 when no suitable reductor is present. Dilute solutions of nitrates of nearly all
metal ions, even the somewhat reducing ones, are stable. |
And NO2 dismutes in dilute solutions, where nitric acid is reduced to NO instead (which is colourless).
How do dilute nitrate solutions of strongly reducing metal ions behave - Sn2+, V2+, Cr2+, Eu2+,
U3+?
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woelen
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Sn(2+) hydrolyses, formation of a precipitate.
V(2+) and Cr(2+) probably cannot be kept for a long time in water, regardless of the presence of nitrate.
Eu(2+) definitely cannot be kept in water for more than a few minutes, regardless of nitrate presence.
U(3+) I don't know. Does this exist in aqueous solutions? I only know of the yellow uranyl and the green U(4+).
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chornedsnorkack
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| Quote: Originally posted by woelen |
U(3+) I don't know. Does this exist in aqueous solutions? I only know of the yellow uranyl and the green U(4+). |
This:
https://en.wikipedia.org/wiki/Jones_reductor
with link to
Mendham, J; Denney, R.C; Barnes, J.D.; Thomas, M. (2000). Vogel's Textbook of Quantitative Chemical Analysis (6th ed.). Pearson Education Ltd. pp.
446–448. ISBN 0-582-22628-7.
lists cations produced by Jones reductor as:
titanium(III), vanadium(II), chromium(II), molybdenum(III), niobium(III) and uranium(III).
I have not heard much of Nb(III) or Mo(III) elsewhere.
What do Ta and W do in Jones reductor?
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ScienceHideout
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| Quote: Originally posted by MeshPL | Technicaly brass, bronze, cast iron (carbon solution , who needs fullerenes?),
all the jewlery and some on, are solutions.
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There is a professor at my university who does a lot with fullerenes! I am pretty sure they dissolve in toluene...
hey, if you are reading this, I can't U2U, but you are always welcome to send me an email!
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