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blogfast25
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SC, I’m sorry but you’ve still lost me: I didn’t link to anything. Instead I looked it up in Brauer and used first NaHCO3, then NH3
(aq) as source of alkalinity to precipitate the hydrated Sn (II) oxide, instead of Brauer’s recommended Na2CO3. Neither of my tests succeeded in
making brown/black anhydrous SnO.
The French pdf however is interesting in the sense that it actually recommends NH3 (aq) as the base and that on heating to 110 C the anhydrous
material can be obtained. So thanks for that.
I think I’ll try this again, this time replacing the supernatant mix of NH4Cl and NH3 by clean water. After all, when converting the faulty SnCl2
that’s what I did and discolouration on heating took place immediately.
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S.C. Wack
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I didn't say anywhere that you linked to anything? Is all this some kind of joke?
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blogfast25
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No SC, it just seems we've got our wires crossed.
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S.C. Wack
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12.6 GB later...F&S's Z. anorg. article says nothing more, except that they are following Ditte's guidelines. It's not worth posting I guess.
Everyone cites F&S (Brauer) as the way to go (the J. Phys. Chem. reference mistakenly gives all the credit to the French article, which they must
not have read). But one of the other Z. anorg. references does a few experiments. So, instead:
Attachment: z_anorg_213_301_1933.pdf (258kB)
This file has been downloaded 654 times
[Edited on 31-8-2012 by S.C. Wack]
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blogfast25
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Quote: Originally posted by S.C. Wack  | 12.6 GB later...F&S's Z. anorg. article says nothing more, except that they are following Ditte's guidelines. It's not worth posting I guess.
Everyone cites F&S (Brauer) as the way to go (the J. Phys. Chem. reference mistakenly gives all the credit to the French article, which they must
not have read). But one of the other Z. anorg. references does a few experiments. So, instead:
[Edited on 31-8-2012 by S.C. Wack] |
That text seems like an interesting monography on SnO, quite complete state of the art, at least up to that moment in time. Thank you.
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AJKOER
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Here is a new source (link: http://tin.atomistry.com/stannous_oxide.html ) with interesting comments on forming SnO. To quote:
"Stannous Oxide, SnO, may be prepared in several ways. It is obtained by heating a mixture of stannous chloride and sodium carbonate until it becomes
black, then washing with water, and drying the residue with a gentle heat in a stream of carbon dioxide. It is also produced by igniting stannous
oxalate out of contact with air, when it is obtained as an olive-green powder; and by precipitating stannous chloride solution with alkali, and
boiling the hydrated oxide thus produced with dilute caustic potash solution; the anhydrous oxide thus formed crystallises in microscopic cubes or
octahedra. A crystalline form of the oxide is also obtained by digesting a nearly saturated solution of stannous oxide in acetic acid of density 1.06
at 56° C. This form of the oxide is red, but quiokly turns black on exposure to sunlight.
The black amorphous oxide easily dissolves in hydrochloric acid forming stannous chloride, and burns when heated in the air forming the dioxide:
SnO(cryst.) + ½O2 = SnO2(cryst.) + 71,000 calories"
[Edited on 13-10-2012 by AJKOER]
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