vano
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Uses of potassium metabisulfite
Hi. Today i bought some potassium metabisulfite. It is pure compound. As a substance I do not use often. Often I make sulfite and sulfur dioxide, once
I made Chevreul's salt and used in aqua regia.
If you have other ideas write here.
I think it is italian.
[Edited on 15-2-2021 by vano]
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Fyndium
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Bisulfite is used commonly to purify high value aldehydes and ketones through adduct formation. The general process is to make a saturated solution of
bisulfite (dissolution is endothermic, so heating or using hot water may be preferable), mix it with the impure product, and if it does not initiate
on it's own, dropping in ethanol slowly until precipitate starts to form helps. Adding too much alcohol will cause the bisulfite itself to precipitate
along with the adduct, so only the minimum amount needed should be used. The adduct formation generates heat, and it is done when the reaction cools
down, and it can be suction filtered and washed with a solvent best suited for the use.
The adduct can be broken with sodium carbonate solution, and if necessary, product that is partially or more soluble in water is extracted with a
solvent. Adduction is considered a high loss process, with 10-20% loss of yield minimum, even with decent practices, but it can be used to make very
highly pure aldehydes or ketones. Generally, other methods of purification are preferable, and adduct is used only as a last resort.
There is a lot of other uses too, as like:
https://en.wikipedia.org/wiki/Bisulfite#Organic_synthesis
Used as a quenchant to remove traces or excess amounts of chlorine, bromine, iodine, hypochlorite salts, osmate esters, chromium trioxide and
potassium permanganate.
[Edited on 15-2-2021 by Fyndium]
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vano
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Thanks. Good reagent. I heard about that. It is well described in clayden organic chemistry book. I agree with you it is useful chemical to synthesis
of warer soluble drugs.
I saw many times it in organic chemistry, but now im interested in uses in inorganic chemistry.
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Bedlasky
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Metabisulfite is universal and cheap reducing agent in inorganic chemistry.
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vano
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Yes.
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