RE: Ferrous to Ferric Oxalate [was Re: patents]

Does H2O2 go bad in hermetic container?

-----Original Message-----
From: Alberto Novo [mailto:alt-list@albertonovo.it]
Sent: 16 Şubat 2006 Perşembe 12:44
To: alt-photo-process-L@usask.ca
Subject: Re: Ferrous to Ferric Oxalate [was Re: patents]

I don't know which is better:
Curtin used a stoichiometric reaction, where you need to know the actual

H2O2 conc.; less H2O2 results in less Fe(III)Ox and some free oxalic
acid.
Fe(II) oxalate is virtually insoluble.
Vichy method (direct reaction between ferric nitrate and oxalic acid)
leads
to free nitric acid, not easy to handle at home.
A third method is probabily better, but I do not recommend unless you
have a
fume hood. From Gmelin (the chemists' Bible): ferric nitrate in conc.
nitric
acid plus oxalic acid, filter and leave the solution concentrating over
sulphuric acid. After a day, separate the crystals and wash them with
iced
water.

Alberto

> I seem to have tried it an a distant past, and I was not happy with
> the procedure, it took an awfull lot of peroxide to kick the ferrous
> to the ferric (probably because hydrogen peroxide isn't very stable,
> the conc. Goes down with time). You're much better of trying the
> method by Vichy
> (sp?) as described on Jeff Mathias his excellent web side,
>
> Cor
Received on Thu Feb 16 04:52:55 2006