[yin]

Hello,

I was preparing Copper acetate from 40ml 9% destilled winegar, 50ml 3% hydrogen peroxide (pharm grade) and 2,75g copper wire. After 24h about 0,5g of copper dissolved into solution, which was clear and deep blue color. I start evaporating it in hot water bath, but now after 2 hours white precipate formed on the bottom of the flask.

My question is, where does the white color from?

I used the copper wire as anode in previous electrolytic experiment preparing the same product as now. I washed it, but not completely. I did filter the solution using a paper towel, which I rinsed very well. Maybe one of above causes introduced impurities. Which is more possible and why?

[Arkcon]

Is the precip white, or more greenish or bluish white?  If so, it is likely one of many complex salts called copper hydroxide.  http://en.wikipedia.org/wiki/Copper%28II%29_hydroxide

[yin]

Thanks for the answer. I boiled the solution down and the white precipate turned out as light blue. In dark solution, these crystals looked really white. Recrystalising right now.

Anyway, I want to use my copper acetate and copper ammonium sulphate, which I am currently preparing, for a copper plating experiment. I used peroxide to start the reaction of sulphuramic acid and copper wire. Peroxide makes it impossible to electroplate with the solution and I don't want to boil again to remove it. Can I use Manganese dioxide to destroy the peroxide and then filter it out?