View Full Version : Ferric or Ferrous Oxalate


Andrew O'Neill
01-21-2007, 06:25 PM
Okay all you Kallitype experts out there...Ferric and Ferrous Oxalte are the same thing, correct? I was told by the place I bought it from that they are the same. There is a little voice inside my head saying, "no, it ain't the same".

colrehogan
01-21-2007, 07:23 PM
No, they aren't the same. The difference is that iron has two oxidation states. Ferric is the higher one (+3), and ferrous is the lower one (+2).

doughowk
01-21-2007, 07:31 PM
They are not the same. But one of the methods for making ferric oxalate is combining ferrous oxalate & oxalic acid (method described in Dick Stevens book). If you are new to Kallitypes (as I am) you should buy ferric oxalate from a reputable supplier (eg, Bostick & Sullivan, Photographers Formulary, ArtCraft Chemicals).

Andrew O'Neill
01-21-2007, 07:58 PM
Thanks guys.

Jordan
01-22-2007, 08:38 PM
I would even say that you should avoid buying ferric oxalate from a place that says that ferric and ferrous are the same thing. They might give you sodium sulfide instead of sodium sulfite on a future order, or something.

Dana Sullivan
01-22-2007, 09:56 PM
When you expose ferric oxalate to UV light it converts to ferrous oxalate, which in turn bonds to the Pt/Pd salts. I suspect that Pt/Pd prints made with a ferrous oxalate solution would be solid black.

Jordan
01-23-2007, 07:35 PM
When you expose ferric oxalate to UV light it converts to ferrous oxalate, which in turn bonds to the Pt/Pd salts. I suspect that Pt/Pd prints made with a ferrous oxalate solution would be solid black.

Dana -- I don't think you'd even get as far as making the print. Mixing a solution of ferrous oxalate with Na2PdCl4 or K2PtCl4 (or any of the related salts used in Pt/Pd printing) would probably cause the instantaneous formation of a precipitate of black Pd or Pt powder.


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