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

Re: converting anhydrous to mono...?

Yes, the recipe I have calls for mono which would add 18 to the anhydrous weight, if I'm not mistaken. So multiplying the mono amount by .885 gives me the weight in anhydrous form...again, if I'm not mistaken.
The form you've referenced has 1.5 molecules of water (sesqui-hydrate?) which adds 27 to the anhydrous weight, giving 165.2, as listed.
I will make sure the developer is on the acidic side...thanks.
----- Original Message -----
Sent: Wednesday, May 20, 2009 9:07 AM
Subject: RE: converting anhydrous to mono...?

Potassium carbonate is listed as K2CO3x1.5H2O FW165.23, for the anhydrous FW is 138.21
I do not see monohydrate. CHeck on this one more time. For the formula listed above you would need 138.21/165.23=0.8365 multiplied by the weight called for by the recipe.
make sure that your developer is on the acidic side. I keep some crystals of undissolved acid on the bottom. Watch the foaming as you add the carbonate.
> Date: Wed, 20 May 2009 08:11:56 -0700
> From: viapiano@pacbell.net
> Subject: converting anhydrous to mono...?
> To: alt-photo-process-l@usask.ca
> Hi all...
> I'm making PO developer today and I need to convert anyhdrous Potassium
> Carbonate (what I have) to its mono (what I need) equivalent in weight.
> Does anyone have the conversion factor and a reference...?
> Much thanks...
> Paul

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