LD5050
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how can I separate Sodium hydrosulfite and sodium bisulfite mixture?
I found a toilet rust remover powder the ingredients are Sodium hydrosulfite and sodium metabisulfite. I would like to separate the two and collect
the Sodium Bisulfite how could I do this?
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Texium
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Firstly, what is the brand? I've been trying to find good OTC sodium hydrosulfite (dithionite) for a while now, so I'm more interested in that
component.
You shouldn't need to separate them though, especially not if you need to use the bisulfite in solution. Dissolving it in water and heating the
solution gently for a while should convert most of the dithionite to bisulfite and thiosulfate. And, if you just need it as a general reducing agent,
using it as-is should be fine.
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Texium
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Thread Moved
15-3-2017 at 21:18 |
j_sum1
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IIRC, Nurdrage uses an OTC source of dithionite in his recent video on a luminescent oscillating reaction. I can't check right now. But I know I
saw it recently.
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LD5050
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so the brand is Iron Out and on it says "rust and stain remover" with a picture of a toilet on it. It says its contains Sodium Hydrosulfite and sodium
metabisulfite. I want the bisulfite to purify benzaldehyde by forming the adduct.
Oh ya I checked the MSDS and it say it contains 20-40% hydrosulfite and 20-40% bisulfite. Along with a couple other things of tiny percentages like
citric acid and Sodium carbonate maybe? if I rember correctly
[Edited on 3-16-2017 by LD5050]
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j_sum1
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If the metabisulfite is what you are after, IME, the easiest OTC source is brewers' suppliers. It is used for disinfecting bottles.
Bisulfites are not too tricky to obtain from SO2 if you have a source of sulfur. (Ask Daffodile for some.  )
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LD5050
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Ya the only brewing supply store is kinda far from me so I wanted to find another option.
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Corrosive Joeseph
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If you do find a decent separation method, please post it.............
Sodium hydrosulfite - AKA - https://en.wikipedia.org/wiki/Sodium_dithionite - is also very useful, it will reduce aldehydes and ketones................ And according to
Weygand and Hilgetag (Preparative Organic Chemistry 1972), it was 'previously much used to reduce carbon-carbon multiple bonds'................
I'm sure there are plenty more applications for it.............
PS - Just buy the metabisulfite at the brew shop.............. 
/CJ
[Edited on 17-3-2017 by Corrosive Joeseph]
Being well adjusted to a sick society is no measure of one's mental health
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Amos
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If you happen to be in the states, I'd suggest getting Bonide Stump Remover at a hardware store; it's pure sodium metabisulfite and goes for like
$6/454g.
The rust remover sounds interesting, since you can react the sodium metabisulfite portion with zinc in solution to get sodium dithionite alone; thus
reducing the amount of zinc you'd need to synthesize it from bisulfite anyway.
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Corrosive Joeseph
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Quote: Originally posted by Amos  | | you can react the sodium metabisulfite portion with zinc in solution to get sodium dithionite alone; |
Quality piece of information there. Hopefully that could be done without even separating a mixture of the two.
Apologies for topic drift..................
/CJ
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LD5050
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I looked around and wasnt able to find the stump remover anywhere. I purchased the rust out tho so any idea on how to purify it so I can use it to
make adducts of ketones would be helpful thanks in advance.
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JJay
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| Quote: Originally posted by Corrosive Joeseph | | Quote: Originally posted by Amos | | you can react the sodium metabisulfite portion with zinc in solution to get sodium dithionite alone; |
Quality piece of information there. Hopefully that could be done without even separating a mixture of the two.
Apologies for topic drift..................
/CJ
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That *is* a quality piece of information. I'm going to have to try that.
As to the OP's question, you could probably dissolve the mixture in water and fractionally crystallize. The sodium dithionite should crystallize
first. Note that oxygen will dissolve in the water and slowly destroy your sodium bisulfite, and this is likely to be a messy procedure with lots of
bumping, difficult filtrations, sulfurous smells, and fairly noxious fumes.
Personally, I would just keep my eyes peeled and pick up a large sack of it at my earliest opportunity or perhaps try making some by burning sulfur.
It's an extremely common chemical.
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