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Specialty Chemistry Forums => Citizen Chemist => Topic started by: science2000 on October 19, 2005, 09:15:03 PM

Title: Mixing HCl and H2O2
Post by: science2000 on October 19, 2005, 09:15:03 PM
Is there any danger in mixing householdperoxide and muriatic acid? That  seems to be the best way to dissolve copper. Yes, I did it on a very small scale already---a squirt of peroxide from a pipette into a small jar with the acid--Didn't smell but a faint amount of Chlorine, and the solution became very green very fast. The copper screw pitted fast.
What kinds of reactions are going on in this a mixture of muriatic acid and very diluted peroxide?
Title: Re: Mixing HCl and H2O2
Post by: science2000 on October 20, 2005, 12:14:52 AM
hydrochloric acid isn't an organic compund. I'd think the only danger is the possible generation of Chlorine. But if the peroxide oxidizes the Copper, and the HCl dissolves the oxide, that's what I feel is happening. I wondered too if this would produce various kinds of oxychlorides.
Title: Re: Mixing HCl and H2O2
Post by: AWK on October 20, 2005, 02:06:34 AM
There is no danger of explosion using diluted (3-5%) hydrogen peroxide and muriatic acid od any concentration. Diluted solution of H2O2 helps to dissolve copper (you may also use NaOCl). Such mixtures are commonly used in hydrometallurgy.
Do this reaction under hood - some Cl2 can be evolved

Note - hausehold hydrogen peroxide do not neccessary contain pure H2O2.
Very often its solutions are prepared from a quite stable solid urea-hydrogen peroxide solvate that contains about 35 % of hydrogen peroxide.
Title: Re: Mixing HCl and H2O2
Post by: science2000 on October 20, 2005, 02:53:34 AM
I'd use hydrogen peroxide because after it oxidizes, it becomes water, thus there aren't unwanted cations. I thought commercial peroxide was 3% pure H2O2 stabilized with 0.001% phosphoric acid, if I remember reading the ingridients on an old bottle some years back. But you're saying now it's some urea compound involved? I'm not sure what reactions that would have with a halogen. I know Chl;orine dissolves in water, anyways, all of those compounds work together and reall digest copper.

Would this peroxide-muriatic acid mixture dissolve silver, or gold, if very powerful oxidizing oxychlorides and free Cl2 are dissolved in water?