U of S | Mailing List Archive | alt-photo-process-l | RE: converting anhydrous to mono...?

RE: converting anhydrous to mono...?


I purchase my potassium carb. from the ChemistryStore.com. It arrives as a
dry crystalline state and stays that way in the sealed bucket. Actually I
never concerned myself about the type of pot. carb. I measure out the pot.
carb. and oxalic acid and mix in a 5 gal. plastic pail. Nothing could be

I use distilled H2O. I check the pH after everything is mixed. It's a bit of
work but not that bad.  

Just remember Macbeth ~ " Like a hell-broth boil and bubble. Double, double
toil and trouble;"

Well not so much trouble just a little work.


-----Original Message-----
From: Loris Medici [mailto:mail@loris.medici.name] 
Sent: Wednesday, May 20, 2009 4:08 PM
To: alt-photo-process-l@usask.ca
Subject: RE: converting anhydrous to mono...?

Don, I haven't done it before but it seems like it's the only correct way
of doing it if you're using uncertain anhydrous potassium carbonate. OTOH,
I don't know if there's a stable crystallized version of potassium


20 Mayıs 2009, Çarşamba, 10:56 pm tarihinde, Don Bryant yazmış:
> Loris and all,
> I'd just add potassium carbonate to the oxalic acid solution (mixed at
> right concentration beforehand) until it doesn't fizz anymore, then add
> minuscule amounts of oxalic acid (patiently) checking the pH of the
> solution every time, until you reach the desired pH level. (pH 6?)
> That's more or less what I do. It works fine and is inexpensive.
> Don