Fidelmios
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Got an impurity in Copper Acetate Synthesis
Hello again,
I feel like I make these threads every month with a new problem. This month is Copper Acetate! I was synthesizing it from a fairly pure sample of
Copper Acetate, where I converted it to Copper Carbonate using sodium bicarb, and then from there I converted the carbonate salt to the Copper
Acetate. When doing this syntheses I wound up getting what I thought was Copper Carbonate that refused to convert to Copper Acetate, so I ended up
using a crazy excess of Acetic Acid. This impurity kept persisting, so I filtered off the solution, and boiled away the excess Vinegar. I let the
solution sit under a fan for 3 days, the purple crystals of copper acetate fell out first and I woke up this morning to a blue almost slime like stuff
covering everything. This stuff had the same appearance as Copper carbonate, but it didn't react to Vinegar. So I thought it might be some left over
Sulfate, but it didn't react to Sodium bicarb. I have noticed that this stuff is a tad heavier and floats to the bottom of my coffee filter when I
poured this stuff out.... what can I do? What is this mysterious substance, and can I salvage my Copper Acetate?
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aga
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If you mention Copper Carbonate again without adding the word 'Basic' in front, blogfast25 might eat you alive.
I have no idea why he doesn't prefer cooking his victims with some onions, garlic, a dash of salt and pepper ...
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RocksInHead
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Quote: Originally posted by aga  | If you mention Copper Carbonate again without adding the word 'Basic' in front, blogfast25 might eat you alive.
I have no idea why he doesn't prefer cooking his victims with some onions, garlic, a dash of salt and pepper ... |
But isn't basic copper carbonate and copper carbonate different? Isn't one CuCO3 and the other Cu2(OH)2CO3?
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careysub
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| Quote: Originally posted by RocksInHead | | Quote: Originally posted by aga | If you mention Copper Carbonate again without adding the word 'Basic' in front, blogfast25 might eat you alive.
I have no idea why he doesn't prefer cooking his victims with some onions, garlic, a dash of salt and pepper ... |
But isn't basic copper carbonate and copper carbonate different? Isn't one CuCO3 and the other Cu2(OH)2CO3? |
Yes, but you are not going to be preparing neutral CuCO3 with aqueous chemistry. You are always preparing basic copper carbonate.
Check out:
https://en.wikipedia.org/wiki/Copper(II)_carbonate
Wherein is says, for example:
"Reliable synthesis of true copper(II) carbonate was reported for the first time in 1973 by Hartmut Ehrhardt and others. The compound was obtained as
a gray powder, by heating basic copper carbonate in an atmosphere of carbon dioxide (produced by the decomposition of silver oxalate at at 500 °C and
2 GPa (20,000 atm)."
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Fidelmios
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I forgot myself my lords. I shall flail myself many times and do 30 NMR analyses for penance.
Seriously though, whatever this goop is I wanna know how to either get rid of it, or make it into something else.
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Fidelmios
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https://cdn.discordapp.com/attachments/169433016626708480/22...
I'm on mobile right now but this is what my filter paper looks like from below.. what should be a dark purple solid is sitting atop this blue-teal
paste. I could wash it with cold water, or cold alcohol and get this off, but it will cost me some of my product. Eating Ramen for 4 days a week says
I would like to keep all the product I can 
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Fidelmios
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So I found that it is indeed Copper hydroxide. I will try to separate them by gravity filtration.
Here is a link that I found helpful http://www.sciencemadness.org/talk/viewthread.php?tid=66247#...
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crystal grower
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If it's really Cu(OH)2 then the most advantageous solution of this problem is adding a little of Acetic acid to make the solution slightly acidic.
If you only separate them, then after some time you will get another layer of Cu(OH)2 because transition metal acetates hydrolyse in water solution
(unless you make it acidic...).
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Fidelmios
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Yeah I did a simple filtration and ended up with a very nice purple solution. I'm allowing it to slowly recrystalizations (in acidic conditions thanks
to Crystal grower) if I can get the rest of the solution to crystalize out with little copper hydroxide I have about 50g of copper acetate to also
recrysralize.
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