Eddygp
National Hazard
Posts: 858
Registered: 31-3-2012
Location: University of York, UK
Member Is Offline
Mood: Organometallic
|
|
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]
there may be bugs in gfind
[ˌɛdidʒiˈpiː] IPA pronunciation for my Username
|
|
Eddygp
National Hazard
Posts: 858
Registered: 31-3-2012
Location: University of York, UK
Member Is Offline
Mood: Organometallic
|
|
Green-bluish solution. Not quite the colour of CuSO4.
there may be bugs in gfind
[ˌɛdidʒiˈpiː] IPA pronunciation for my Username
|
|
bbartlog
International Hazard
Posts: 1139
Registered: 27-8-2009
Location: Unmoored in time
Member Is Offline
Mood: No Mood
|
|
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.
The less you bet, the more you lose when you win.
|
|
chemrox
International Hazard
Posts: 2961
Registered: 18-1-2007
Location: UTM
Member Is Offline
Mood: LaGrangian
|
|
http://en.wikipedia.org/wiki/Copper
you oxidized it with the peroxide as you might have expected
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
|
|
CHRIS25
National Hazard
Posts: 951
Registered: 6-4-2012
Location: Ireland
Member Is Offline
Mood: No Mood
|
|
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.
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
|
|
vmelkon
National Hazard
Posts: 669
Registered: 25-11-2011
Location: Canada
Member Is Offline
Mood: autoerotic asphyxiation
|
|
There is this thread from 2005
http://www.sciencemadness.org/talk/viewthread.php?tid=4866
|
|
Eddygp
National Hazard
Posts: 858
Registered: 31-3-2012
Location: University of York, UK
Member Is Offline
Mood: Organometallic
|
|
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]
there may be bugs in gfind
[ˌɛdidʒiˈpiː] IPA pronunciation for my Username
|
|
UnintentionalChaos
International Hazard
Posts: 1454
Registered: 9-12-2006
Location: Mars
Member Is Offline
Mood: Nucleophilic
|
|
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.
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
|
|
tetrahedron
Hazard to Others
Posts: 210
Registered: 28-9-2012
Member Is Offline
Mood: No Mood
|
|
carbonayto, carbonahto
|
|
sargent1015
Hazard to Others
Posts: 315
Registered: 30-4-2012
Location: WI
Member Is Offline
Mood: Relaxed
|
|
If you heat the CuSO4 and bicarb while mixed in solution, you will get the carbonate.
|
|
vmelkon
National Hazard
Posts: 669
Registered: 25-11-2011
Location: Canada
Member Is Offline
Mood: autoerotic asphyxiation
|
|
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
|
|
Eddygp
National Hazard
Posts: 858
Registered: 31-3-2012
Location: University of York, UK
Member Is Offline
Mood: Organometallic
|
|
By the way, any method to test for SO2?
there may be bugs in gfind
[ˌɛdidʒiˈpiː] IPA pronunciation for my Username
|
|
tetrahedron
Hazard to Others
Posts: 210
Registered: 28-9-2012
Member Is Offline
Mood: No Mood
|
|
allegedly SO2 reacts with MnO2 to give MnSO4.
|
|
ElectroWin
Hazard to Others
Posts: 224
Registered: 5-3-2011
Member Is Offline
Mood: No Mood
|
|
SO2 gas is also smelly.. it has that brimstone smell. it should be obvious if you make some.
|
|
Eddygp
National Hazard
Posts: 858
Registered: 31-3-2012
Location: University of York, UK
Member Is Offline
Mood: Organometallic
|
|
Yes, I mean, it emits a really pungent odor, choke-like
there may be bugs in gfind
[ˌɛdidʒiˈpiː] IPA pronunciation for my Username
|
|
tetrahedron
Hazard to Others
Posts: 210
Registered: 28-9-2012
Member Is Offline
Mood: No Mood
|
|
that can be said of almost any useful compound in amateur chemistry =D
|
|
Eddygp
National Hazard
Posts: 858
Registered: 31-3-2012
Location: University of York, UK
Member Is Offline
Mood: Organometallic
|
|
Lol
there may be bugs in gfind
[ˌɛdidʒiˈpiː] IPA pronunciation for my Username
|
|
barley81
Hazard to Others
Posts: 481
Registered: 9-5-2011
Member Is Offline
Mood: No Mood
|
|
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.
|
|