Re: Sodium carbonate "Washing soda"

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From: Ryuji Suzuki (rs@silvergrain.org)
Date: 07/02/03-10:50:35 AM Z


From: Yu rei <nanocrystals2003@yahoo.co.jp>
Subject: Re: Sodium carbonate "Washing soda"
Date: Wed, 02 Jul 2003 21:13:47 +0900 (JST)

> Well, unless someone on the list NOW reads the lable amd
> tells us something different is on the box or in some lab
> report somewhere, I think we have closure on this.

The box I tested did not say anything about hydration of sodium
carbonate. My test result was nearly perfectly quantitatively
monohydrate.

Also, someone from pure-silver called up Arm & Hammer and their answer
was monohydrate.

If Arm & Hammer said their product is anhydrous, I think this is far
from closure... leaves more questions now. Anhydrous carbonate is
hygroscopic and absorb water and carbon dioxide gas from air. When
this happens, some of the carbonate will be bicarbonate.

> The differing amounts of water determined by Ryuji and
> mentioned by Sil, can possibly be attributed to the
> anhydrous material picking up some water somewhere along
> the way.

It is possible, but if this is the case, I'd expect a significant
fraction of the carbonate would be converted to bicarbonate, and
should be detected as reduction of titratable base (total alkalinity).

If this is important to you, I think the only way to find out is to
run your own test. The article I sent you should give you enough idea
of what to test... or, just buy sodium carbonate monohydrate from a
company who provides their lab test data.

Ryuji

--
Ryuji Suzuki
"Reality has always had too many heads." (Bob Dylan, Cold Irons Bound, 1997)

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