17 grams ferric oxalate
3 grams oxalic acid
1 gram EDTA
63 ml. distilled water
I put this into a beaker, and gently heat it on a hot plate whilst
continually stiring. At first it looks like paint, but when it gets hot
enough the solids dissolve and the solution turns a clear yellow/green
(under a safelight it looks black). At this point the solution is quite
hot (but not boiling). I would suggest you try heating your solution a
bit more. ...and by the way, I use Bostick & Sullivan's ferric oxalate
(and have for the past 15 years) without any trouble. They also have it
available in solution. I know that Richard Sullivan went to great pains
to come up with a way of manufacturing a really good ferric oxalate. He
reads this list from time to time, so perhaps we could persuade him to
comment. Richard, are you there?
- David Fokos
>
> I just bought some Ferric Oxalate from a major chemical house. The problem
> is that I can't get it to dissolve (a 24% solution). Half of it has dissolved
> into the familiar green solution and half is just a lump of yellow semi-solid!
> I've been working at it with mild-heat and a magnetic stirring device, but
> very little of it is dissolving. I've added around .7g of Oxalic Acid
> and nothing else. Since I don't have a hot-plate and the stirrer isn't working
> I began wondering if this Ferric Oxalate (I believe its a tetra-hydrate) may
> just be more difficult to dissolve. Are different types of Ferric Oxalate
> (in regard to the amount of water in the solid) more difficult to dissolve
> than others? I read in the Bostic&Sullivan catalog that the addition of some
> EDTA can often help it dissolve- how much should I add for a 100ml?
>
> Any help would be appreciated,
> Adam
>
>