Eddygp
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Awkward reaction
Lacking sodium carbonate, I tried to react copper sulfate and sodium bicarbonate to make copper carbonate. i then had the idea to add some diluted
H2O2 at 5% conc. or so to the mixture.
It almost instantly started fizzing. I could not recognize any smell, but it all changed to a dark brown solution. What have I created? Some sort of
weird sodium cuprate?
EDIT: Actually, it was a suspension of incredibly fine black particles in a greenish solution. I believe the blackish powder is cupric oxide, but...
the green solution?
[Edited on 14-11-2012 by Eddygp]
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Eddygp
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Green-bluish solution. Not quite the colour of CuSO4.
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bbartlog
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Stoichiometry? Was there any precipitate prior to the addition of H2O2? I would expect some sort of cupric carbonate (blue) to precipitate. As for the
green color, no idea. Maybe the dissolution of other ions (sodium sulfate etc.) changes the color chemistry of the copper somehow.
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chemrox
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http://en.wikipedia.org/wiki/Copper
you oxidized it with the peroxide as you might have expected
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CHRIS25
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You can also get sodium carbonate by simply heating the sodium bicarbonate in an oven, it will drive off the water. Then that's it.
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vmelkon
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There is this thread from 2005
http://www.sciencemadness.org/talk/viewthread.php?tid=4866
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Eddygp
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Th solution was actually blue, meaning there is some unreacted CuSO4.
And by the way, I searched for topics bearing the name CuSO4. I am sorry if I opened a topic similar to that one, but as I found any of these
characteristic having CuSO4 in its name or text... 
[Edited on 15-11-2012 by Eddygp]
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UnintentionalChaos
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When I last tried to precipitate CuSO4 solution with NaHCO3, the solution turned a dark blue- darker than the original CuSO4. Presumably, this was a
soluble carbonato complex of some sort. I'm unsure about following the H2O2 addition, though.
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tetrahedron
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carbonayto, carbonahto
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sargent1015
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If you heat the CuSO4 and bicarb while mixed in solution, you will get the carbonate.
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vmelkon
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You don't need to heat it. CuCO3 forms right away while CO2 bubbles off. Most bicarbonate are unstable and decompose to carbonate and CO2.
The alkali metal bicarbonates are stable, in solution and solid form.
The alkali earth metal bicarbonates are stable in solution (cold) but I think they can't be isolated in solid form.
CuSO4 + 2 NaHCO3 -> CuCO3 + Na2SO4 + CO2 + H2O
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Eddygp
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By the way, any method to test for SO2?
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tetrahedron
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allegedly SO2 reacts with MnO2 to give MnSO4.
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ElectroWin
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SO2 gas is also smelly.. it has that brimstone smell. it should be obvious if you make some.
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Eddygp
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Yes, I mean, it emits a really pungent odor, choke-like
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tetrahedron
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that can be said of almost any useful compound in amateur chemistry =D
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Eddygp
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Lol
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barley81
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A common test is to hold a stirring rod with a drop of dilute KMnO4 solution over the vessel. If there is SO2, the drop will become colorless.
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