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microcosmicus
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@woelen I was quoting my ceramic supplier's catalog,
where they list the compound as SnO. Of course, they
might be mistaken or perhaps both oxides are used
because they will turn into the same product upon
firing anyway.
@MagicJigPipe Particle size?
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woelen
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Does the catalog show pictures? If the material is white, then it is SnO2, if it is almost black, then it is SnO.
I know this, because I have had a little dispute with an eBay seller, who sells all kinds of materials. One of the chems he sells is tin oxide, 88.1%
tin.
http://cgi.ebay.co.uk/TIN-OXIDE-Sn-88-1-500g_W0QQitemZ320082...
This corresponds to SnO, which I really wanted because of its reactiveness and allowing one to make tin(II) salts. I ordered the material, and I
received a bag with 500 grams of white powder, which is extremely inert. The MSDS for SnO tells its dark brown or dark blue. The MSDS for SnO2 tells
it is white.
I complained about this. The seller told me I am the first one, who complained, but his other customers usually are not home chemists but ceramists
 , and the latter kind of people is less picky  . Things were arranged in a satisfactory manner (the seller has offered me other
materials at reduced price, such that I had the SnO2 for free) , but he did not want to change the stated percentage of Sn in the oxide.
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microcosmicus
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Unfortunately, the catalog is pretty much text-only 
Since the material is rather expensive ($41.60 per
pound, i.e. $91.63 for a kilogram) I doubt I will buy
some in the near future. However, I did notice that
the catalog lists Chemical Abstracts Number
18282-10-5 so you might be able to look that up
to see what oxidation state of tin it refers to.
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-jeffB
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| Quote: | Originally posted by microcosmicus
Unfortunately, the catalog is pretty much text-only
Since the material is rather expensive ($41.60 per
pound, i.e. $91.63 for a kilogram) I doubt I will buy
some in the near future. However, I did notice that
the catalog lists Chemical Abstracts Number
18282-10-5 so you might be able to look that up
to see what oxidation state of tin it refers to. |
Google makes it SnO<sub>2</sub>. I just stopped into my local (central North Carolina, USA) pottery-supply store, and they have it in
half-pound bags for $30/lb, but it's sounding like it's not an especially good buy. They also had V<sub>2</sub>O<sub>5</sub>
for $28/lb, along with the of the usual suspects at what appear to be reasonable prices. Now, if only they carried aluminum dust...
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12AX7
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| Quote: | Originally posted by -jeffB
Now, if only they carried aluminum dust... |
They do, and it's even already combined with oxygen, ready for pottery purposes.
Tim
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microcosmicus
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@jeffB
For comparison, tin metal retails at $16/lb, so you can
save a lot by rolling your own Sn compounds.
@12AX7 My pottery shop also carries cryolite, grinding
balls, and sieves so you could reduce your Al2O3 and
grind it to dust if you felt so inclined 
[Edited on 5-1-2008 by microcosmicus]
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-jeffB
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| Quote: | Originally posted by 12AX7
| Quote: | Originally posted by -jeffB
Now, if only they carried aluminum dust... |
They do, and it's even already combined with oxygen, ready for pottery purposes.
Tim |
If only there were some way that I could reduce it, perhaps by igniting it with another metal... no, wait.
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MagicJigPipe
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I still can't determine whether I have cobalt (II) or (III) oxide. Perhaps it's a mixture of both?
It dissolves in concentrated HCl solution forming a dark blue solution. It very slowly dissolves in water forming a very lightly blue solution. I
might go so far as to say that it's "sparingly soluble" in water.
It's supposedly "cobalt blue" for use in pottery. Sources claim that this is CoO but, if so, shouldn't it form a pink solution with HCl because of it
forming hydrated CoCl2?
This is really bugging me. What other experiments could I perform to determine what this crap is?
Also, Wikipedia claims that CoO can be had from Co2O3 by heating it above ~975*C. That makes sense but that is VERY hot and I don't think I have a
suitable container that can reach temperatures that high at the moment.
[Edited on 5-24-2008 by MagicJigPipe]
"There must be no barriers to freedom of inquiry ... There is no place for dogma in science. The scientist is free, and must be free to ask any
question, to doubt any assertion, to seek for any evidence, to correct any errors. ... We know that the only way to avoid error is to detect it and
that the only way to detect it is to be free to inquire. And we know that as long as men are free to ask what they must, free to say what they think,
free to think what they will, freedom can never be lost, and science can never regress." -J. Robert Oppenheimer
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not_important
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Try diluting the concentrated solution, the pink hydrated Co(II) dehydrates in strong acid and will complex with Cl ion in high concentration.
From my experience it is often a mixed oxide, mostly Co(II) but also a little Co(III). Dissolving it in hot hydrochloric acid releases some chlorine,
but less than Co2O3 or even Co3O4 should.
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