BauArf56 - 22-8-2019 at 09:20
I’ve mix a solution of CuSO4 and H2O2 (3,6%) to synthesize sulfuric acid. The solution after some drop of H2O2 changed color: from initial blue
becomes dark yellow with black precipitate (CuO?). Exit some bubbles from the yellow liquid, Was H2SO4?
AJKOER - 25-8-2019 at 09:47
Please repeat your experiment with different brands of hydrogen peroxide, some of which can be used internally (mouth) and others which can only be
used externally (skin).
If you get the same results, then you may have perhaps eliminated the role of additives in some of the chemistry you have observed.
Also, was your solution exposed to air for long periods or any sunlight?
Did you first dissolve the CuSO4 in tap water?
[Edited on 25-8-2019 by AJKOER]
BauArf56 - 25-8-2019 at 12:42
Thanks for answer. The hydrogen peroxide that i used was at a 3,6% concentration (too high to use for mouth, it’s for external use). I checked
ingredients, and i have found “Sodium diethylenetriamine pentamethylene phosphonate”, so maybe this reacted. I will prove with highest H2O2
concentration, then i will update.
P.S. the hydrogen peroxide was in a opaque bottle, and i haven’t leave it at air.
Bedlasky - 26-8-2019 at 13:26
I think that the ingredient chelating copper and form yellow complex. Precipitate should be very dark olive green - this is copper peroxide CuO2 which
easily decompose in to CuO and O2. But this peroxide is formed in alkaline media not in slightly acidic. I try added some 3,5% peroxide in to the
CuSO4 solution in soft tap water and nothing happend (only some oxygen was release from solution). Did you add some bicarbonate, carbonate or
hydroxide? Was your solution of CuSO4 clear before additon of H2O2? Did you CuSO4 dissolve in distilled water or in tap water (tap water was soft or
hard?)? How much precipitate was formed?
BauArf56 - 27-8-2019 at 02:48
I haven’t add nothing except CuSO4, water and H2O2. The solution maybe was not clear, because i used tap water, this water was soft, anyway.
Yesterday i add to the solution NaCl, and it start bubbling like chlorine. (if you did NaCl solution electrolysis, the chlorine exits by solution with
a effervescence-like) I was thinking that gas was hydrogen chloride (anhydrous HCl) so i abandoned all, because that gas is very toxic. What do you
think of this? Was HCl?
Bedlasky - 27-8-2019 at 04:07
H2O2 oxidize chlorides in to chlorine.
Soft tap water don't have enough bicarbonates to form precipitate. Maybe your CuSO4 containt some basic copper carbonate which form CuO2 with
peroxide.
[Edited on 27-8-2019 by Bedlasky]