Sciencemadness Discussion Board

Trouble with getting nickel(II) to dissolve in ammonia.

Foeskes - 12-11-2017 at 18:12

I am trying to separate nickel from iron and chromium. I first dissolve the metal in HCl and precipitate the metals out with sodium bicarbonate. Then I tried to dissolve the nickel and chromium in ammonia but it doesn't seem to dissolve much (really light blue).

ninhydric1 - 12-11-2017 at 18:39

First, use NaOH to convert the chromium to soluble chromates while precipitating the iron and nickel as their corresponding hydroxides.

Iron(III) acetate is insoluble in water while nickel(II) acetate is soluble in water. I believe allowing any iron(II) ions to oxidize to iron(III) would allow separation using acetic acid or a soluble acetate salt. Filter the iron(III) acetate precipitate, allowing easier separation than using ammonia.

EDIT: Some grammar fixes.

[Edited on 11-13-2017 by ninhydric1]

Foeskes - 12-11-2017 at 19:05

I don't really have any concentrated acetic acid, only vinegar.

ninhydric1 - 12-11-2017 at 19:17

Vinegar should work too, but you would have to deal with a substantial amount of water.

DraconicAcid - 12-11-2017 at 20:22

How dilute is your ammonia if nickel won't dissolve in it?

Foeskes - 12-11-2017 at 20:59

It's 25%