APO
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Sodium Metabisulfite Mystery
I heard on here that Sodium Metabisulfite decomposes to Sodium Oxide and Sulfur Dioxide on Heating. I could not find anything else on this, so I tried
to test it. I added some Sodium Metabisulfite to a skillet and set it to high heat. There was definitely loads of Sulfur Dioxide being evolved, and
when I added water there was a lot of initial bubbling (probably cause it was still hot) and then it started etching away at the skillet's non-stick
coating. I didn't have anything on hand to test the pH of the solution, can anyone else please test this?
Here is the only balanced equation I could come up with:
Na2S2O5 = Na2O + 2SO2
"Damn it George! I told you not to drop me!"
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unionised
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How about
Na2S2O5 --> Na2SO3 + SO2
?
(Which is about a zillion times more likely)
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Acidum
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I know that potassium metabisulfite decomposes to SO2 and K2SO3 at around 200oC, and that both (Na and K
metabisulphite) release SO2 with acids.
If You are looking at wikipedia as starting point (which in some time you will realise is bad thing) than try to follow its reference...takes you to
page with no such information.
Just check pH with universal indicator strip.
...and then I disappeared in the mist...
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blogfast25
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Quote: Originally posted by APO  | | I heard on here that Sodium Metabisulfite decomposes to Sodium Oxide and Sulfur Dioxide on Heating. |
Here? It wouldn't be the first time there some misinformation on this board.
Sodium metabisulphite decomposes to sulphite. Sulphite itself would only start decomposing at insanely high temperatures and it's not clear what it
would result in.
There are no easy ways to prepare Na2O.
[Edited on 10-5-2013 by blogfast25]
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APO
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Thanks guys.
"Damn it George! I told you not to drop me!"
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