RE: Making Ferric Oxalate

Richard Sullivan (richsul@roadrunner.com)
Mon, 09 Dec 1996 09:49:18 -0700

Terry Kings says:

>Now I know how to make the ferric oxalate recipe work*, incidentally my
stirring
>rod assumed an interesting sculptural shape during the peroxide reaction the
>other day, I want to have a go at making ferric ammonium citrate. to get
>consistency.
>
>Terry
>
>* When the peroxide reaction stops and the mixture is still brown just keep
>adding oxalic acid and the mixture will turn green and the precipitate wilkl
>dissolve. Keep adding the acid untill the ferri reaction test works. The test
>involves putting a series of drops of a 0.5 % ferri solution onto a plate and
>then adding a drop of the green stuff to each ferri drop until the
resulting two
>combined drops of ferri and the green stuff go pale yellowy green rather than
>blue.
>

I am assuming you are making it from ferrous oxalate. The best way to do it
this way is to pack the beaker in dry ice to cool it down before adding the
peroxide. This will slow down the violent reaction. If no dry ice is
available, ice and alcohol or ice and salt will help. Phil Davis of "Beyond
the Zone System" fame gave me this tip over a decade ago.

This method is not to be attempted by the squeemish.