mnick12
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Purification of ethylsulfuric acid?
So I have about 60ml of ethylsulfuric acid that I made by refluxing anhydrous sodium bisulfate with denatured alcohol. After refluxing I cooled and
vac filtered the acid from the sodium sulfate, I then rinsed the sodium sulfate with ethanol to try and remove any acid that remained behind. Now I
have about 60ml of a thick oil that has a slight yellowish color. Now my question is what would be the best way to remove the ethanol without
decomposing the ethylsulfuric acid? Would stripping the ethanol under vacuum work? If possible I would like to avoid the formation of diethylsulfate.
Thanks!
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sabbath06
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Ethyl hydrogen sulfate boils at 209 degrees C while ethanol boils at 78 degrees C so simple distillation seems like it would be the way to go
but I could be wrong!
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Nicodem
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Are you sure? Where did you got that info from? At which pressure?
I would expect it to decompose at considerably lower temperatures and even if not, that temperature is simply too low for a compound like that at 1
atm pressure.
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turd
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Probably Wikipedia (http://en.wikipedia.org/wiki/Ethyl_sulfate) and it clearly states that 209°C is the decomposition point. Apparently some people are not aware of
the meaning of the "(decomp.)" notation for melting and boiling points.
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Nicodem
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Wikipedia! What a surprise. How come people so easily gave up on verifying references and trust Wikipedia so lightly?
SciFinder gives no info about the boiling point. The only physical data it gives is the density (1.3657 g/cm3 at 20 °C). Though one of the papers
describing the synthesis of ethyl sulfuric acid says it starts decomposing as low as 125 °C:
| Quote: | Huaxue Shiji, 13 (1991) 190. CA 115: 158460
Abstract: Stirring 95% EtOH (excess) with concd. H2SO4 in the presence of Na2SO4 at 25 gave 98.8% EtOSO3H which was heated at 125-140 under reduced
pressure to give 87.2% Et2SO4. |
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ThatchemistKid
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Heating ethyl sulfuric acid with ethanol should yield ether as that is the intermediate in the general over the counter diethyl ether synthesis.
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