khourygeo77
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Preparation of Copper (I) oxide from copper?
Any idea how this can be done?
I have tried many ways but always end up with copper II oxide
Also, how can I transform the copper metal into a green copper in big quantities? (I could manage to transform only the surface of the copper (very
small portion) which isnt practical at all
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JJay
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I've never done it, but I know that copper (ii) oxide is sometimes used as a mild oxidizer, resulting in the formation of copper (i) oxide as a side
product. If you want copper (i) oxide, you could first dissolve copper in sulfuric acid and then do a reaction with Fehling's solution or Benedict's
reagent and (for example) glucose.
I think green copper is typically copper sulfide and that typically only the surface is green, even on very large and century old copper pieces like
the Statue of Liberty... there seems to be a lot of information on metalworking sites on turning copper green... it depends on what materials you have
available.
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nezza
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Yup. Dissolve the copper to give a solution of copper (II) ions. Add tartrate and Alkali until you get a deep blue solution. This is Fehlings
solution. Boil with a mild reducing agent like glucose. The red precipitate that forms is copper (I) oxide.
If you're not part of the solution, you're part of the precipitate.
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khourygeo77
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I see it is difficult to find a reducing agent
https://en.wikipedia.org/wiki/Reducing_agent#Common_reducing...
I could find none of these at home.
I'll be trying to make iron II acetate solution by dissolving iron in H2O2 + vinegar then adding it to a copper acetate II solution. Do you think it
will work? Or should I neutralize it with an alkali like baking soda beforehand ?
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JJay
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You can probably find fructose at your local grocery store or lactose at your local pharmacy... table sugar is nonreducing, but honey contains a lot
of reducing sugars.
I think you'll probably get iron (iii) acetate if you use hydrogen peroxide with acetic acid to dissolve iron.
Making pure iron (ii) acetate requires taking care to keep air from oxidizing the iron to iron (iii): http://www.ims.demokritos.gr/people/tbou/iron_acetate.html
[Edited on 16-5-2017 by JJay]
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Magpie
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Brauer (forum library) has some methods. I know I've made it because I have some in my cabinet. I will have to check my notebooks to see how I made
it.
The single most important condition for a successful synthesis is good mixing - Nicodem
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khourygeo77
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Quote: Originally posted by JJay  | You can probably find fructose at your local grocery store or lactose at your local pharmacy... table sugar is nonreducing, but honey contains a lot
of reducing sugars.
I think you'll probably get iron (iii) acetate if you use hydrogen peroxide with acetic acid to dissolve iron.
Making pure iron (ii) acetate requires taking care to keep air from oxidizing the iron to iron (iii): http://www.ims.demokritos.gr/people/tbou/iron_acetate.html
[Edited on 16-5-2017 by JJay] |
Do you think molasse will work instead of honey? I saw it contains reducing sugars
Interesting about the Iron II acetate, how do you think I can obtain the powder without exposing to air? This always happened to me only when the iron
acetate solution was getting dried and not when it was in solution
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JJay
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I am pretty sure that around here, most molasses is mostly sucrose, but you can obtain molasses that is high in reducing sugars, that would probably
work.
Oh and as far as obtaining the powder without exposing it to air... that usually requires special equipment, but with some creativity and ingenuity,
you can improvise.
[Edited on 16-5-2017 by JJay]
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Magpie
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I checked my inventory and what I have is CuO. I know I have seen Cu2O (a red powder) most likely when doing the Fehling's test for reducing
compounds like glucose or aldehydes.
I suppose you could use the Fehling's reagents to prepare Cu2O. Instructions for making the reagents are shown on p. 192 in Brewster (forum library).
The single most important condition for a successful synthesis is good mixing - Nicodem
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khourygeo77
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| Quote: Originally posted by JJay | I am pretty sure that around here, most molasses is mostly sucrose, but you can obtain molasses that is high in reducing sugars, that would probably
work.
Oh and as far as obtaining the powder without exposing it to air... that usually requires special equipment, but with some creativity and ingenuity,
you can improvise.
[Edited on 16-5-2017 by JJay] |
Distilling the solution would pretty much do the work? Especially if the vapor passage is a very small beaker, no?
And is it necessary to react the copper II with an alkali before adding the reducing agent? Cant I add the reducing agent immediately to the copper II
ion?
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JJay
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I don't know... I think it would depend on what the reducing agent is.
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Booze
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Is it possible to make copper carbonate by dissolving copper in a hot solution of vinegar and hydrogen peroxide, then adding baking soda and filter
it, and turn that to copper (i) oxide by then boil it down and heat it above 1200 degrees?
[Edited on 16-5-2017 by Booze]
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Melgar
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You want reducing sugar? Well, this sounds like a fun experiment if I ever saw one:
https://en.wikipedia.org/wiki/Inverted_sugar_syrup
Sucrose rotates light polarization to the right, but hydrolyze it with heat and a pinch of citric acid, and it'll form a mixture of glucose and
fructose that rotates light polarization left. You can even use light polarization as an indicator of when the reaction is done.
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ninhydric1
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You could attempt a single displacement reaction using copper metal and a tungsten, mercury, silver, gold, or platinum salt in an aqueous solution due
to the reactivity series of the metals, then heat it up to decompose the resulting copper salt into an oxide. A silver or mercury(I) salt would be
preferred. But this method isn't very cost-efficient.
According to the Wikipedia page for copper(I) oxide, you can use sulfur dioxide to reduce copper(II) solutions, but there isn't much information about
that. This method, if works, could be a useful procedure for obtaining copper(I) solutions.
[Edited on 5-16-2017 by ninhydric1]
[Edited on 5-16-2017 by ninhydric1]
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symboom
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Electrolysis of copper and zinc produces a yellow precipitate copper as the anode and zinc as the cathode in a salt water solution produces a yellow
vrown percipitate
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MeshPL
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Copper I oxide can be made from copper ii solutions just by addition of sulfite and maybe changing pH to more basic.
It is also produced when copper is oxidised anodicaly in NaCl solution, cathode may also be copper.
If you want to make "green copper" you can try percipitating copper carbonate by addoing carbonate/bicarbonate to copper ii solution, filtering the
percipitate and finally drying it.
Interestingly, anodic oxidation of copper in NaOH solution produces black goop (CuO?) adhering to the anode which, after taking the anode out of a
solution and exposed to air, produces a green crust on the anode (green copper?).
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nezza
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If you want a nice easy reducing sugar try honey - it is nearly pure fructose.
If you're not part of the solution, you're part of the precipitate.
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chemplayer...
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Have a look: https://www.youtube.com/watch?v=aVD4fjs8Umk
You're almost certainly going to have to dissolve the copper to form a soluble (II) salt and then reduce it. We found that the best reducing agent was
sodium bisulfite. Use something too powerful and the result is copper (I) oxide which is too fine to actually filter properly.
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Oscilllator
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If you are in america you can buy high frucose corn syrup very cheaply which is a reducing sugar I believe. If you aren't (like me) just grab a cup or
so of normal table sugar, add a dash of HCl or other strong acid and then boil it for an hour or so. Costs virtually nothing and I can verify it works
quite well. Alternatively I remember a thread on here a while back in which solutions of copper were reduced with ascorbic acid, which can be bought
relatively cheaply online as vitamin C.
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Amos
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If you treat copper(II) sulfate solution with ascorbic acid, you will end up with a fine precipitate of powdered copper metal but also a yellow or
green supernatant liquid; keep adding ascorbic acid until the supernatant is yellow. Adding sodium hydroxide solution to this produces a yellow
precipitate of what is rumored to be hydrous copper(I) oxide; it can simply be dried in air to produce the reddish form we all know and love.
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