roastedchicken - 21-9-2016 at 15:21
Hi guys
I'm new here so pleased to meet you all. I'm trying to generate chromium (III) ions as cheaply as possible for a test. I've tried dissolving some
Cr2O3 I bought but found that it was calcinated and was insoluble in strong acids and alkalis.
I was thinking of CrCl3 or Cr(III) sulfate but it seems like they are both insoluble. Does anyone have a suggestion as to how I can do so? Thanks!
j_sum1 - 21-9-2016 at 15:38
If your starting point is Cr2O3 then you will find that it is pretty inert. You can fuse it with KNO3 which gives you Cr(VI) Then use your favourite
reducer to bring it back to Cr(III).
I don't know of any other treatment of standard Cr2O3 that will actually get you anywhere without going via hexavalent chromium.
OTOH, if your Cr2O3 is very fresh (such as the residue of ammonium dichromate decomposition) then I believe that it will respond to strong mineral
acids.
[edit]
Cr2(SO4)3 is soluble in water.
[Edited on 21-9-2016 by j_sum1]