how do you turn copper sheet green, ie oxidised.?
913403
Just leave it out and let the air get busy.  The copper will turn green all on it's own.  The Statue of liberty is green because it was made of copper.
418443
Copper can react with nitric acid on two different ways based on the concentration of nitric acid.\n\nIf cold and dilute nitric acid is used, then the reaction yields copper(II) nitrate, nitrous oxide(N2O) and water.\n\nCu + HNO3 ----- Cu(NO3)2 + N2O + H2O\n\nIf hot and conc. nitric acid(a stronger oxidising agent) is used, the reaction yields copper(II) nitrate, nitrogen dioxide(NO2) and water.\n\nCu + HNO3 ----- Cu(NO3)2 + NO2 + H2O\n\nP.S. - Balance the equations yourself(might take some time but use the oxidation no. method)
42156
It is very easy to clean copper jewelry and keep it a beautiful copper color.  You don't have to have a store-bought cleaner, you can use things that can easily be found around the house in most any kitchen; vinegar, lemon juice, or ketchup!  (Click this link White Tiger Tracks Store to go to my  store where you can find great copper rings, necklaces and bracelets like my His & Hers Copper Baby Boomers Bracelets )\n\nPlace your copper jewelry in a glass, or plastic container, not metal.  I use a drinking glass.  Pour enough vinegar over it to completely cover it.  Let stand for 5-10 minutes.  Rinse.  Dry.  You're done!
1172374
You could try passing it through carbon, but that may also remove iron.  You would need to try it with known solutions.\nYou may need to go to AA or ICP analysis.
840734
Hmm, you could try some of the more powerful solvents - xylene, acetone etc, leave them soaking overnight.\n\nIt will burn off too but if not VERY careful you end up "bluing" the metal - depending in what it is made of.\n\nI am curious about the reason to remove the lacquer. I remember having to di it once for a friend who wanted certain items to be conductive but that's a while different story,\n\n(He used a blow torch on his to remove the laquer but there WAS some minor "bluiing" from the heat where he had let the ring get too hot.
1083835
orange and lime green. if not that then lime green
300790
Here's a link for annealing copper wire.  I don't know if that's what you want.
571388
Cu + 2H2S04 --> CuSO4 + SO2 + 2H20\n\nCu (copper) is oxidized, because it loses 2 electrons to enter into the +2 state.\n\nThe sulfuric acid is the oxidizing agent, because it oxidizes the copper and is itself reduced to form sulfur dioxide. (Compare the oxidation states. Half of it remains as SO4- because it takes 2 equivalents of H2SO4 to react with Cu, due to the mole to mole ratio.)\n\nI'd do this reaction in the fume hood, though. SO2 is an irritant to your lungs.
916549
2Cu + O2 ---> 2CuO,          \nThis is copper oxide or cupric oxide or copper( II )oxide\n\n4 Cu + )2---> 2Cu2O\nCopper also combines with oxygen as Cu2O, cuprous oxide , or copper(I) oxide
446103
Part A\n\nReduction: 3e^- + 4H^+ + NO3^- = NO + 2H2O    Eo = \nOxidation:                 Cu  = Cu^2+ + 2e^- Eo =\n\nMultiply the reduction half equation by 2 and the oxidation half equation by 3 (so that you have 6e^- in both) then add together to get:\n\n3Cu + 8H^+ + 2NO3^- = 2NO + 3Cu^2+ + 4H2O\n\nNow Eo cell = Eo cathode - Eo anode = 0.96 - 0.34 = +0.62V\n(Note: you do NOT multiply the Eo values by the number of electrons in the half equations because Eo is a voltage, measure of electrical pressure.\n\n\nPart B\n\nThe Nernst equation can be found at:\n\nhttp://www.science.uwaterloo.ca/~cchieh/cact/c123/nernsteq.html
121669
Once again, you can follow my directions for making anhydroyus copper sulfate in your previous post. Anhydrous copper sulfate is white or a very pale blue-green if you didn't keep it dry enough, which is as close to colourless as you are likely to get. Water of course is colourless.\n\nThe chemicals themselves are fairly easy to find.\n\nIf you have access to the school's chemical supply you should be able to get some phenolphthalein. Add a few drops of baking soda and Bob's your Uncle.
903862
Sorry Voyager. Copper is not so reactive a metal that it will react with sulphuric acid.\nYou need either solid copper (II) carbonate or solid copper (II) oxide for the salt.\nSince it is a sulphate, sulphuric acid is used together with the solid.\nHeat the acid so that the reaction can proceed at a faster rate. Add solid till no more will react (no bubbles of gas produced, and the solid remains insoluble). This is to ensure that all the acid is used up. Filter to remove unreacted solid and heat the filtrate, which is the copper (II) sulphate solution, till saturated (approximately 1/3 to half the original volume left would be a good gauge). Let the hot saturated copper (II) sulphate solution cool and after some days, when the excess water evaporates off, you should get hydrated copper (II) sulphate crystals.\nDo not heat till dryness as this will evaporate off the water of crystallization needed for the blue copper (II) sulphate crystals to form. Without the water of crystallization, you would get anhydrous copper (II) sulphate powder (white) and not the blue crystals.\n\nHope this helps :)
963455
Copper C-145000\n\nCopper  Includes Ag + Te  \nPhosphorus  Other deoxidizers may be used  \nTellurium  0.4 - 0.7
3048
If your skin turns green that means that it is not true silver, it is only coated. This coat however must be applied by charging the metal ions and dropping it in silver ions so that htey cling.  Fake silver coats arent ionized therefore the silver can be substituted for nickel.  The green substance is the nikel staining your skin as it comes off of the metal.
998526
hmm. copper is a tricky metal. firstly conc. sulphuric acid and nitric acid are the only acid that would react as they are also strong oxidising agents. What happens when u dip the turning is that the copper is oxidised into copper(II)oxide and the sulphate ion is reduces to sulphite SO3 2-. I think so but not too sure if i'm right.
888667
Cu2S + 12HNO3 -> Cu(NO3)2 + CuSO4 + 10NO2 + 6H2O\n\nThere you go.
1185928
put your object in a concentrated solution of HCl (muriatic acid) , the silver will precipitate as silver chloride, you can now filter the solution and keep the silver chloride. Then add ammonia to the silver chloride to solubilise the AgCl. Then put a copper wire in the solution, the silver will precipitate on the copper, put copper until no silver is appering. you can now filter the liquid to obtain pure silver