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JohnWW
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You may be able to use the stuff as a paint pigment, to tint existing paint, or by mixing it with clear polyurethane varnish or boiled linseed oil.
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entropy51
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I try not to let heavy metals get into the sewer, BUT
The CuSO4 I buy at the hardware store is intended to be dumped into the sewer to kill tree roots invading the sewer line. The label has an EPA
Registration number on it, but also states that it's harmful to fish and aquatic organisms.
Isn't it likely that the Cu plates out on the Fe sewer pipes and mostly ferrous SO4 is left in the water heading out to sea? That's what happens in a
beaker of CuSO4 when I add steel wool to it in order to make Cu powder.
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itchyfruit
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I don't go dropping anything down the drain unless i'm absolutely sure it's ok to do so,entropy51 was just having his customary dig about my general
incompetence!!!
Funny you should mention peracetic acid,as i did do a little test before i tried the CU+GAA+H2O2 approach,1ml of each on a little AL cup and set about
it with a mapp gas blow torch hoping to detonate it!! nothing just evaporated, USELESS 
I opted for KOH as mine is from a large AR grade chemical supplier,whereas my NAOH is just sink unblocker(prills)from the local hardware store.
I don't think i'd be able to make much paint out of what i made,i suppose i could paint the mail box(on a dolls house) 
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itchyfruit
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My copper acetate looks like woelens. wahooooo
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woelen
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And can you tell us more about the exact procedure, used to make it? You used H2O2 and copper metal? This is another (possibly new, at least for some
of us) procedure. We learn the most of it, if you provide us with exact procedures, and numerical values for amounts of used chemicals.
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UnintentionalChaos
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Quote: Originally posted by itchyfruit  | I don't go dropping anything down the drain unless i'm absolutely sure it's ok to do so,entropy51 was just having his customary dig about my general
incompetence!!!
Funny you should mention peracetic acid,as i did do a little test before i tried the CU+GAA+H2O2 approach,1ml of each on a little AL cup and set about
it with a mapp gas blow torch hoping to detonate it!! nothing just evaporated, USELESS
I opted for KOH as mine is from a large AR grade chemical supplier,whereas my NAOH is just sink unblocker(prills)from the local hardware store.
I don't think i'd be able to make much paint out of what i made,i suppose i could paint the mail box(on a dolls house)
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It's quite hard to make any appreciable amount of peracetic acid.
Look up industrial synthesis methods- high concentrations of H2O2 and acetic acid, sulfuric acid catalyst and up to 10 day reaction times.
A mixture of vinegar and dilute H2O2 agressively attacks lead and is commonly used to clean gun barrels.
Simply bubbling air through the acetic acid will also dissolve copper, albeit slowly.
[Edited on 8-17-09 by UnintentionalChaos]
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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itchyfruit
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My H2O2 method didn't work !! I used your OH method, but i think i jumped the gun a little with my celebrations it did look like yours but now it's
completely dried it has a bit of a green tint and some powdery white crystals on the surface.
By the sounds of it i was a bit impatient with the H2O2 method,and i didn't use any sulphuric acid in the peracetic acid or leave it long enough,but i
don't think i'll temp fate by trying it again just yet
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woelen
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These powdery white crystals most likely are either sodium sulfate or sodium carbonate (from excess NaOH). You really need to rinse the black
precipitate of CuO (which is formed after heating the suspension of Cu(OH)2 in water) in order to get rid of excess NaOH and/or sulfate.
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itchyfruit
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I'm going to start again from scratch, i must have got something wrong i'll double check all my measurements and make sure i get rid of any excess
NAOH next time.
It's weird because i thought i had to much GAA as it really smelt vinegary...
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chemoleo
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You can also try the CaAc2 (from CaCO3 and white vinegar) and CuSO4 route, this way you get CuAc2 and CaSO4. CaSO4 can be filtered off reasonably
well. I've done that a long time ago in a 5 liter quantity. This was then reacted with Pb metal to get PbAc2 (see the big PbO2 thread I think).
Anyway, it works becuase CaSO4 is badly soluble, so the amount of CaSO4 left in the CuAc2 solution is small.
By the way, woelen, I also did that a while ago (getting CuO from Cu[OH]2), but the resulting CuO was still a worse thermite than CuO from the pottery
supply. Even though this CuO was roasted on red heat, and guaranteed free of Na2SO4 (it was washed for eons). It's an interesting powder actually,
behaving/swirling almost like a liquid when hot!
[Edited on 18-8-2009 by chemoleo]
Never Stop to Begin, and Never Begin to Stop...
Tolerance is good. But not with the intolerant! (Wilhelm Busch)
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woelen
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| Quote: Originally posted by chemoleo | By the way, woelen, I also did that a while ago (getting CuO from Cu[OH]2), but the resulting CuO was still a worse thermite than CuO from the pottery
supply. Even though this CuO was roasted on red heat, and guaranteed free of Na2SO4 (it was washed for eons). It's an interesting powder actually,
behaving/swirling almost like a liquid when hot!
[Edited on 18-8-2009 by chemoleo] |
I did not dry the CuO, because I wanted to make Cu(OAC)2 from it (and that can better be done with the wet stuff than with some inert dry powder). I
can imagine that the roasting in red heat leads to loss of some oxygen and that part of it was decomposed to Cu2O. Your powder might have been some
mixed oxide, somewhere between CuO and Cu2O. Such a mixed oxide definitely will perform worse in thermite reactions than pure CuO. On the other hand,
I expect that such a mixed oxide still looks black and not red.
If you still have some of your roasted CuO left, then try dissolving some in concentrated HCl. If the solution becomes very dark brown, almost black,
then it contains copper(I) and copper(II) and then my theory is right, if the solution becomes green/brown and not really dark, then it only contains
copper(II) and then my theory is wrong and another explanation must be found for the different behavior in thermites.
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chloric1
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I make other copper salts from store baught copper sulfate a different way. I make a solution of say 20% copper sulfate and it is moderately heated
to 60 celsius. When solution is complete, i slowly add solid sodium bicarbonate until effervescense stops. The resulting basic copper carbonate is
easier to filter and requires less washing. The copper sulfate should be somewhat dilute to keep most of the sodium sulfate that forms in solution.
Copper is a weakly basic metal and the carbonate decomposes very easily on heating producing a pure cupric oxide. The basic carbonate can also be
used for your copper acetate. I used this method to make cupric formate.
Fellow molecular manipulator
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zed
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Refluxing colloidal precipitates, like Calcium Sulfate, Calcium Phosphate, or the classic Silver Chloride.....In an effort to increase crystal size,
and thereby filter-ability......Well, it's a pain in the ass.
A long time ago, in a galaxy, far, far away.......I donated this procedure, to my friend Carl Abrams, who was writing a text book.
Simply heat your reactant solutions near boiling. Then slowly, pour one solution, into the other.
Since your Phosphate, Sulfate, Chloride, product....is slightly more soluable in very hot water, your initial crystals, form more slowly, and thereby
attain a significantly larger size.
They simply fall out of solution.
Thus the simple expedient, of pre-heating your solutions, renders the otherwise maddening Phosphate-type of determination.....Easy.
The classic experiment, in my chem days, was the Chloride determination, via precipitation with Silver Nitrate. First, form an un-filterable Chloride
precipitate. Then, boil endlessly in attempting to coagulate. Finally, filter, oven dry, and weigh.
At stake, was most of your chemistry grade.
Man, what a mess. The procedure made people hate chemistry.
[Edited on 30-8-2009 by zed]
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Nathaniel
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I have a problem with copper acetate preparation, but before I start describing everything, here's what troubles me:
1. CuCO3*Cu(OH)2 + acetic acid( large excess) --> uncomplete reaction
2. Heating the solution of copper acetate --> quite some blue-green percipitate forms (probably some basic copper salt)
I've tried to make copper acetate many times, usually with basic copper carbonate, made from sodium carbonate and a soluble copper salt (sulfate,
chloride). Even though I used excess of acetic acid (usually 9% vinegar, but I tried pure acetic acid as well) the carbonate wouldn't react completely
even after a few days on warm temperatures. I never actually determined the amount of undissolved carbonate, but it's usually approximately 25% or
more. I plan to repeat the experiment again on Friday so I'd appriciate if someone could help me 
I also had problems when I tried to boil down the filtrate of the above reaction. Even before boiling point a green-blue percipitate starts to appear
and the amount of it even increases with boiling. It's probably some basic salt of copper which is surprising because there's still a lot of acetic
acid present in solution. This also happens when I let the filtrate to partially evaporate and get some really nice crystals, but when I try to
dissolve them in hot vinegar they decompose to the blue-green percipitate mentioned before. I couldn't find this mentioned anywhere so I'm turning to
you guys for advice why this happens and how to prevent it (more the later as I have many theories why it happens but can't find the solution).
[Edited on 26-12-2012 by Nathaniel]
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Rich_Insane
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Will acetic anhydride substitute for GAA in the reaction of Cu2O to Cu(OAc)2, or will I have to add water?
Update: Heated 20 grams of CuSO4.5H2O with 3.5 grams of NaOH to produce Cu(OH)2. Boiled this down in an attempt to create CuO, but by the time all the
water boiled away, there was still a lot of Cu(OH)2. So I decided to simply isolate the chunky green-black material and add 15 ml of Ac2O plus 20 ml
of water. After an hour or two, there was a beautiful deep blue clear liquid and some blue-colored crystal precipitate on the bottom, in addition to
some white precipitate (sodium sulfate?). I added 20 more ml of water to hydrolyze any remaining Ac2O. The solution quickly turned cloudy.
Now there is a slimy gray-blue precipitate on the bottom (probably sodium salts discolored by copper acetate) in addition to the deep blue transparent
layer. Does anyone know how I might remove these impurities? It's not absolutely necessary: I plan to use the Cu(OAc)2 as a catalyst in a different
reaction. However, the purer my reagents, the more accurate my calculations.
[Edited on 30-12-2012 by Rich_Insane]
[Edited on 30-12-2012 by Rich_Insane]
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Metacelsus
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I've never had problems with the basic copper carbonate + vinegar reaction. As long as the basic copper carbonate is pure (e.g., washed with copious
water after synthesis), it should react completely with vinegar. I make mine by reaction of root killer (CuSO4*5 H2O) with washing soda (NaCO3)
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Metacelsus
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Also, as to the blue-green precipitate, it might be crystals of copper acetate. Copper acetate monohydrate is blue-green, but you probably know best.
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Metacelsus
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If you want to make copper acetate, use basic copper carbonate, not copper hydroxide. It's easier and cheaper to make.
2 CuSO4 + 2 Na2CO3 + H2O → Cu2(OH)2CO3 + 2 Na2SO4 + CO2
The basic copper carbonate precipitates.
Make sure to use an excess of acetic acid when making the acetate.
I have done this reaction several times with vinegar as my acetic acid source, and it works just fine. It's a pain to remove the water though.
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Eddygp
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Copper in a H2O2/AcOH mixture will work out slowly but OK.
there may be bugs in gfind
[ˌɛdidʒiˈpiː] IPA pronunciation for my Username |
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Metacelsus
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Have you ever heard of peracetic acid?
H2O2 + CH3CO2H -> CH3CO3H + H2O
H2O2 + AcOH is not something I'd like to try.
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Sedit
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I made some Copper acetate not to long ago using electrolysis of a EtOH solution and NaCl and Copper electrodes. Dunno what the yields where but I was
just playing and was happy that I formed any Copper acetate by this method. Im sure it could be stream lined and improved using various electrolytes
if the folks here put there minds to it.
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
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Nathaniel
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Thanks guys, I know the basic copper carbonate method is the cheapest and I've somehow managed to dissolve almost all the precipitate, but needed 4eq.
of vinegar instead of 2...(until now I always added ca. 2,5eq.) The precipitate formed when the solution is heated is not copper acetate because it
wouldn't dissolve in vinegar or distilled water...strange that only I'm having this problem 
I'm planning to make a large amount of copper acetate for crystal growing (1 kg ) so I wanted to make the synthesis as efficient as possible.. I guess I'm stuck with slow evaporation..
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DraconicAcid
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My students make this material every semester, for a % yield lab. We start with copper shavings, dissolve in nitric acid, precipitate the basic
carbonate (which gets washed well with water, and then acetone, so that it is less pasty to work with). The basic carbonate is then reacted with 50%
acetic acid, and the solution is stuck in ice to get most of the product out. I haven't had much luck with growing crystals of it, but I never seem
to get good results with that. One thing I have learned is that if hang a seed crystal in a solution of copper(II) acetate, do not suspend it with a
copper wire.
If you're getting a precipitate when you heat the solution, then perhaps your acetic acid is too dilute, and you're getting a basic copper(II)
acetate?
(First post!)
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Nathaniel
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I just restarted making a large batch of copper acetate so I noticed your post a bit late, but yes, it's possible it's the basic salt that's the
problem... I've just recently found out that "basic copper sulphate" exists as well - it's formula is something like
Cu4(OH)6SO4 or something similar so I got scared a bit that there's some sulphate in my copper acetate as well (just
btw  )...
I was thinking about using stronger acetic acid (I have some) but copper acetate is quite poorly soluble so I would end up adding extra water
anyway...
If I manage to make the crystals anyway, I'll post the pictures
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blogfast25
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7.2 g/100 ml in cold water isn't that poorly soluble (Wiki). And 20 g/100 ml in hot water (Wiki) is someting that could be exploited: from a hot,
saturated Cu(OAc)2 with excess acetic acid to suppress hydrolysis, crystals of the salt should be formed on cooling.
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