Quick way of making Copper (II) Oxide

[DONMAN]

I was fooling around and I discovered quite an expedient way of creating copper (II) Oxide. I stripped some copper wires and then I submerged them in house hold bleach ~3% (NaClO). Then I slowly added 3% H2O2 till the solution stopped bubbling off the H2 (I assume).

3CU(s) + NaClO(aq) + H2O2(aq) --> H2(g) + 3CuO(s) + NaCl(aq)

Is that right?

Do you have any other ways of making Copper (II) Oxide?

I hope to do this on a larger scale and make some really nice Thermite with some Mg. :D

[c.Tech]

(ag)? Don’t you mean (aq) or aqueous?

And copper II oxide has the chemical formula CuO so your equation must be wrong.

Another way of making CuO is by electrolysis of copper in water, but why make it when you can buy it pure from pottery stores?

[DONMAN]

Yes, did mean (aq) that was a type-O. There now my equation works. This process works extremely well, and fast in comparison to electrolysis. I have a very strong source of dc current and it took forever with copper electrodes. This is much faster and I am sure its cheaper(considering the electricity and time consumed for the electrolysis process). If you cant find copper wire use pennies, although this may be slower. Bleach is cheap and so is hydrogen peroxide. I could buy this from a pottery store pre-made... but where is the fun in that. It's like making a really good cake from scratch, you just feel more accomplished than if you would have just mixed some pre-made crap. Also I don't know where the nearest pottery store is. :D

[PeterB2]

Good work...now I can try another method for copper sulfate! I'll have to try this method sometime. Hopefully, I'll have a chance to get some good 30% H2O2 from the local pool store--or can you just use the 3% crap with some success?

[DONMAN]

I am using the 3%~ crap. The thing is if you use 30% your going to have to use 10 time the amount of bleach that you would normally to make your 30% fully react!

Now if you got some pure NaClO and some 30% percent H2O2 then you could seriously lower the volume required for the reaction. Does any one know where/how to get pure or concentrated NaClO? I know you can't just boil bleach down, its got too much NaOH and other thickener crap in it.

[Universal]

Use Ca(ClO)2, from the pool store remove the insoluable mixer and dissolve as much as possible in water. NaClO pure is a dangerous chemical and is very hard to get (where I come from), it is a liquid I think.

[Cobalt.45]

Thanks for that, Donman. Just saved me a trip to who knows where, to buy some.

I'll have a blue comp yet, hopefully.

[DONMAN]

I cant find copper sulfate, so I will attempt to make this and add sulfuric acid.

[PeterB2]

I work at a retirement community (in the dining room), which is a very new facility, and I had to go to the laundry room to get some linens and I noticed a little container above one of the pieces of machinery that said, "When flashing, add pure bleach."

Being curious (and stupid) I went over to open the lid and take a look at the substance. The smell (VERY strong bleach smell) filled the room almost suffocated me making breathing very difficult. However, I was able to catch a glance at the substance inside: a white fine powder of assumedly pure NaClO.

Now I still have no idea where the average person would go to get the stuff, but professional launders (especially at newer facilities) might have some of it.

[Universal]

I doubt that would be pure NaClO, first of all it is unstable, it is a liquid, and pure bleach, or bleach powder is a 70% strength mixture of calcium hypochlorite. Calcium hypochlorite smells very strong of chlorine, I know ;).

[oregon-machinist]

SNIPPED....If you cant find copper wire use pennies, although this may be slower. SNIPPED

If you attempt to use pennies, be very sure they are all Pre-1982, as a matter of fact, I would even go pre-81 to be sure!!!

Post 1982 pennies are 99 % Zinc, with a Copper Flash ([plated).

Also, prior years for pennies (pre-82) are now worth approximately three cents each BY WEIGHT, though it is illegal now, to melt them and sell it as scrap....

Hope that Helps someone...

[Microtek]

I use NaOH to precipitate Cu-salts as Cu(OH)2, then boil the suspension to decompose that to CuO and water.

[Aqua_Fortis_100%]

3CU(s) + NaClO(aq) + H2O2(aq) --> H2(g) + 3CuO(s) + NaCl(aq)

Is that right?

don't work

i've tried by putting some fresh Cu wires inside of a plastic cup and added bleach just o cover. after, adding some 3% H2O2 slowly and the stuff fizzed a lot and a slight smell of chlorine was sprayed in my backyard. actually the right reaction, after search more, is the H2O2 reacting with bleach and forming Oxygen (but i'm not sure of what the rxn lead to chlorine..maybe a side reaction).. if you let the copper reacting with bleach ALONE, this will form a black layer on material, but i'm still not sure if this is copper oxide or oxychloride..

the fastest way to do is as Microtek said: use NaOH(aq) and CuSO4*5H2O(aq)(or whatever copper II soluble salt you have on hand), react them, decant/wash/decant/wash... reapeat several times to ensure the Cu(OH)2 obtained being really FREE NaOH (which can be dangerous , specially if you is planning to use in CuO/Al thermite), and finally , drive out the water by simple bolling them and heating more strongly the black residue(be watchful, the crappy black thing can spread in violent manner and fall in your skin/eye..) .

another old and theoretically simple stuff to make CuO is apply red heat to copper things (coins, wires, etc) and scrape all black part (seems to be very messy, though)

a better and promissing method is put whatever thing made of copper into a strong ammoniacal solution, add a ammonium salt (eg (NH4)2SO4 ) and then bubble air thorough this solution for several hours (eg use an innexpensive aquarium pump to do). your solution will goes to be very nice blue and depending of your reagents and conditions most of the copper will be dissolved.. the atmospheric oxygen does the trick. this mean which you can use oxidizers to do: 3% H2O2 ,etc..but make the things more expensive and can be dangerous (i've tested with 3% H2O2 and this developed lots of heat of the almost simultaneous eat of the copper coin i've put on the cup and leaving the blue solution)..

after do this, you can decant/filter to remove unreacted copper, and heat (OUTSIDE!!!) the solution which will lose ammonia and the complex made before being destroyed to release more ammonia and ppt at same time your nice and usefull CuO.

[megalomania]

My pennies in household ammonia have recently gone from the light blue of hexaaqua copper to the dark purple of copper tetraammonium compound. I boiled the liquid in the microwave and what appears to be copper oxide formed (a black precipitate). I also obtained this black precipitate by conventional heating (to rule out a microwave effect with copper).

I should test to see if copper sulfate would better be reacted with ammonia. Ammonia is easier to get and cheaper than sodium hydroxide now that Red Devil Lye is off the market. If a copper and ammonia compound does form, microwaving should produce a precipitate.

The reaction that you experimented with, aqua, sounds like it may be possible, but is one of those technical theoretical reactions that happens to a small degree, not a main reaction that goes to completion.

There are many complex chemical reactions that CAN happen, but we are interested in a reaction that goes to completion, i.e. giving a substantial quantity of product. Aqua's experiment demonstrated this. This is why practical experimentation always beats theory, or rather why theory always needs experimentation.

[krick]

An as fast as simple way to produce small amounts of copper oxide can be done like this:

Melt some ammonium nitrate, add copper to the liquid and keep heating it. The copper will soon be solved and the solution will turn blue immediately.

Then keep heating until all left over AN has decomposed and finally the formed copper nitrate will decompose quickly producing a cloud of NOX!! and copper oxide.


For your own safety:
Be careful, NOX!! will be formed in quit big amounts; probably it shouldn't be used more than 10g at once because of the risk of a detonation, but I'm not sure at all.

Glassware should better be left out, stainless steel will do its task.

[DONMAN]

The chlorine smell is simply the gas given off by the reaction splattering the solution causing the bleach to disperse into the air giving off the chlorine smell.

[Atra]

I don't know if this is correct, but I've been making copper chloride for years through the reaction of H2O2+Cu=CuO+H2O CuO+2HCl=CuCl2+H2O. Furthermore if not enough acid is used a black layer of silt develops on the bottom that turns green and is instantly dissolved with the addition of more acid. Wouldn't this mean that H2O2 by itself oxidises copper?

[Cindor]

Wouldn't this mean that H2O2 by itself oxidises copper?
H2O2+Cu=CuO+H2O Don't you think you've answered yourself ?
You don't even need to UTFSE, just read what you previously wrote !

And yes H2O2, is, in fact believe it or not, an oxidizer.

[PeterB2]

I don't know what it is with me and copper salts, but now I'm trying to make Cu(NO3)2.

I made some the old fashioned way with nitric acid. But who wants to waste nitric acid?

Would it be possible to use a metathesis reaction with a copper salt (like copper sulfate or oxide) and a common nitrate?

Another interesting thing I read is that in the laboratory, copper nitrate is used to generate nitric acid by decomposing it and bubbling the gases into a cold solution of water. Has anyone heard of this?

[megalomania]

Peter, I am curious to know this as well, so I just looked it up... Turns out you can make copper nitrate (cupric nitrate technically) by boiling a nitrate salt with copper, copper hydroxide, or copper carbonate. Copper carbonate in particular should work best. You can make copper carbonate by adding a solution of sodium carbonate (washing soda, also by boiling baking soda, sodium bicarbonate) to a hot copper sulfate solution. Copper carbonate precipitates from solution.

[tranquillity]

Wouldn't the simplest way to make relatively pure copper nitrate be to simply mix (in water) commonly available copper sulfate and calcium nitrate? Calcium sulfate would precipitate. For higher purity choose a metal nitrate with a more insoluble sulfate like barium or lead.

[PeterB2]

Actually, Mega, copper nitrate is even easier than that: copper sulfate (I just used the root killer stuff from the hardware store) reacts directly with baking soda in a solution at room temperature (tried it as referenced in "The Joy of Chemistry"). Just make sure both solutions are saturated, and presto! about 5 seconds later you have a nice insoluble mass of copper carbonate. Through the reaction with any mineral acid, you should be able to make just about any corresponding copper salt.

Though with this method, you'd still have to waste/use nitric acid for copper nitrate.

I'm going to try your method for making copper nitrate as soon as I get back to my lab...looks promising. If that's relatively expedient, that might be a viable way of producing nitric acid cheaply without a distillation rig.

[Thermiteisfun]

So I've been trying to synth Copper nitrate with electrolysis of KNO3, I had a conversation about it with my friend who is in orgo 2 now and she concurred with me on the theory.

Here is what I did:
I took 20 grams of KNO3 finely powdered and dissolved it into the smallest possible amount of near boiling, distilled water (25 ml).
After that I ran 12v at 1.25 amp with copper electrodes, the reaction resulted in a white gelatinous precipitate with a blue solution and what I assume to be hydrogen which I confirmed with a flame test . NOx was evolved as well, it is my assumption that more NOx will evolve with higher current.

After a few minutes the solution turned black with what I believe to be copper hydroxide floating on top and copper(II) oxide suspended in the solution... The electrolysis caused an awful amount of heat which lead to the decomposition of the Copper Nitrate. I'm going to try with a water bath to regulate the temperature.

I told her this and she said "oh god it's crazy! it's like got a bunch of H2O and OH attached to it with a billion numbers (the precipitate). I think dropping the wire in and heating the solution works to if I remember right, I did that reaction in chem2" (at which point she spilled hot soup on her crotch ending the conversation).

If anybody knows the solubility and formula of the precipitate, please tell me. This could be an extremely easy way to make copper nitrate.

Edit 2: now that the solution has settled, it appears to be a VERY dark blue and cleans my silver very well :D , there is a hint of green though.

Edit 3: After the solution had fully settled, I decanted and put a paper clip in....Nothing! Galvanized nail.... NOTHING! No plating occured at all, it appears that this is not Copper nitrate!

Links I found:
http://www.scienceforums.net/forum/showthread.php?t=15987
http://mooni.fccj.org/~ethall/2046/ch18/electrol.htm
http://www.scienceforums.net/forum/showthread.php?t=16006

[Pyroman]

(ag)? Don’t you mean (aq) or aqueous?

And copper II oxide has the chemical formula CuO so your equation must be wrong.

Another way of making CuO is by electrolysis of copper in water, but why make it when you can buy it pure from pottery stores?

Last year i prepared some copper II oxide by elctrochemical method with water with common table salt dissolved in it.
After the process it must be water washed several times in order to remove NaCl traces.
The salt incerases drastically the condutivity of water reducing the loss of energy by warming the solution. It reduces the amount of voltage requied to get good amperage.
Note there is de amperage that makes the "conversion" not the voltage.
Happy new year.:)