Re: Dichromates ???

From: Katharine Thayer ^lt;>
Date: 11/09/05-12:03:51 PM Z
Message-id: <>

Stephen Wild wrote:
. I find it hard to understand why the
> dichromates have a tendency to fog (based on many post I saw) if nothing
> special happens when they are dry, assuming of course the solution is kept
> in the dark or "UV dark".
> I have many more dum questions like this one, I hope you'll forgive me.

Hi Yves, don't apologize for asking questions, that's how we all learn
something, by someone asking a question.

It's not the dichromate by itself that fogs, so much as the dichromate
when it's mixed with a colloid and coated as a thin film on paper. This
fog occurs of course when the dichromated colloid film is exposed to UV,
but also proceeds in the dark (the dark reaction) especially if the
surrounding air is very humid.
Katharine Thayer
Received on Wed Nov 9 19:58:20 2005

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