Sciencemadness Discussion Board

Tetraaminocopper dihydroxide

Chemorg42 - 24-2-2021 at 13:28

So I'm in the middle of a tetraaminocopper dihydroxide prep, and I have several questions:
I currently have a filtered blue copper hydroxide paste drying on a watchglass and dish. I know that copper hydroxide slowly oxidizes in air, but how long can I leave it out to dry? How can I clean the insoluble residue from my equipment?
Thanks in advance.

symboom - 24-2-2021 at 14:09

Ammonium hydroxide is used to dissolve the insouble residue If the copper hydroxide oxidizes to copper oxide a ammonium hydroxide solution will hydrate the copper oxide and convert it to copper hydroxide. You can also form the product by using copper wire and ammonium hydroxide it would take much longer.

DraconicAcid - 24-2-2021 at 14:31

Blue copper(II) hydroxide will not oxidize in air, but it may dehydrate to the oxide. Hydrochloric acid should take the stains right off.

Chemorg42 - 24-2-2021 at 18:05

OK, thanks for the responses.

Bedlasky - 24-2-2021 at 22:05

You can try to wash copper hydroxide with some volatile solvent like ethanol, methanol, acetone, diethylether, methyl acetate, methyl formiate etc. to speed up drying. Copper hydroxide don't dehydrate quickly, but after a day in solution you can observe some black spots in blue precipitate. But when it is dry, it's perfectly stable (I have one kilo of it with very decent purity and it doesn't have any black spots).