Bedlasky - 25-6-2019 at 12:40
Hi.
I tried today oxidize Co(OH)2, Ni(OH)2 and Cu(OH)2 by bleach. I had in test tubes solutions of these metals. I added in to each test tube few drops of
bleach and small amount of NaOH. Dark brown to black precipitates were formed. In cobalt case I suppose that precipitate was CoO(OH), but what is
nickel and copper precipitates? NiO(OH) and CuO(OH) or something like that? Black copper precipitate was releasing some gas (maybe oxygen or
chlorine). Nickel and copper precipitate are soluble in 10% H2SO4 to Cu2+ and Ni2+, cobalt precipitate only slowly dissolve to Co2+. All precipitates
have oxidation properties.
DraconicAcid - 25-6-2019 at 14:39
Nickel might have been Ni2O3 or NiO(OH), but I suspect the copper was only CuO. What do you mean by "All precipitates have oxidation properties"?
Bedlasky - 26-6-2019 at 04:00
They reacted with sodium metabisulfate in acidic media.
If copper sulfate wasn't oxidized, why didn't precipitated blue copper hydroxide? Solution wasn't hot.