Re: which dichromate

To: alt-photo-process-l@usask.ca
Subject: Re: which dichromate
From: Judy Seigel <jseigel@panix.com>
Date: Fri, 09 Oct 2009 23:29:13 -0400 (EDT)
Comments: alt-photo-process mailing list
Delivered-to: alt-photo-process-l-archive@www.usask.ca
In-reply-to: <98766a900910091313v3587590cmf47381c4c0f74345@mail.gmail.com>
List-id: alt-photo-process mailing list <alt-photo-process-l@sask.usask.ca>
References: <98766a900910091313v3587590cmf47381c4c0f74345@mail.gmail.com>
Reply-to: alt-photo-process-l@usask.ca


On Fri, 9 Oct 2009, Keith Gerling wrote:

Does anyone know a simple method of determining whether a substance is
Potassium vs. Ammonium dichromate?

Mix a batch at the solubility of the ammonium dichromate: (13 grams to 50 cc distilled water) and see if it all goes into solution. If it does, it's ammonium.

If it's potassium, which is only about half as soluble, 50 cc would take only about 6 grams of the chemical.

As for am di being "faster," as I understand it, ammonium dichromate is only "faster" because there's a larger amount of it in a given amount of solution (as above).

J.

I just started using a fresh batch of

what is supposed to be Pottasium dichromate and now I'm getting very bad
results: staining and what looks to be overexposure.  Whatever it is, I am
using a saturated solution.  Isn't Ammonium dichromate "faster"?

Follow-Ups:
- Re: which dichromate
  - From: Keith Gerling <keith.gerling@gmail.com>

References:
- which dichromate
  - From: Keith Gerling <keith.gerling@gmail.com>