re:Dichromate

Sil Horwitz (silh@iag.net)
Thu, 02 Apr 1998 20:55:14 -0500

At 11:26 AM 1998/04/02 -0800, Paul Simon wrote:
>Potassium Dichromate, in or out of solution, is indefinitely stable. It is
>sold by Bureau of Standards in solution as a primary reference titration
>standard. I've used it in the lab and found it's titer never changed. It
>is a strong oxidant. Perhaps it reacted with the bottle cap liner?

Unless it was dissolved in chemically pure distilled water, more likely it
reacted with all the guck that's in most of our tap waters. I know our
"drinking" water here has algae (which can be readily oxidized) and calcium
(calcium chromates are insoluble - and heavy metal chromates make good
pigments!).

Sil Horwitz, FPSA
Technical Editor, PSA Journal
silh@iag.net
Visit http://www.psa-photo.org/