andy
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Ethanol + H2SO4 + O3
I've been doing this experiment, and the substance doesn't smell like acetic acid or ethanol, was wondering if it could have made ethyl acetate.
I'm guessing
CH3CH2OH + H2SO4 + O3 = H2O + O2 + -SO4
-SO4 + CH3CH2OH +O3 = CH3COOH + H2SO4
I've added 15grams NaCl, 10ml sulfuric acid, and 30% ethanol, there is a slight smell of acetic acid, it has a Titanium electrode, and powered by a
15kv NST
[Edited on 28-3-2014 by andy]
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WGTR
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What is it that you're trying to do? Oxidize ethanol to acetic acid?
I only see one wire going into the container. How is the cell configured?
Are you sure that you're making ozone?
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andy
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"Oxidize ethanol to acetic acid? " Yep, well more make -SO4 ions to strip the hydrogen from ethonal, wouldn't ozone/hydrogen peroxide react with
sulfuric acid?
Ozone is being made, it smells like ozone, the Al foil on the bottom below the glass is one plate, and the salt/ethanol mix is the other. The ozone is
being made inside the container.
[Edited on 29-3-2014 by andy]
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WGTR
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Here's a partly relevant (and otherwise useful) reference:
The Catalytic Partial Oxidation of Ethyl Alcohol
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hissingnoise
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| Quote: | | I only see one wire going into the container. How is the cell configured? |
The second wire is connected to alufoil beneath the container ─ like some kind of arbitrary hybrid of plasma-tube and electrolytic cell?
Ooops! Typo edit!
[Edited on 29-3-2014 by hissingnoise]
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andy
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Thanks for the link WGTR
| Quote: |
The second wire is connected to alufoil beneath the container ─ like some kind of arbitary hybrid of plasma-tube and electrolytic cell?
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[Edited on 29-3-2014 by andy]
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hissingnoise
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| Quote: | | The ozone is being made inside the container. |
Ozone is obtained by passing oxygen or air into a high-voltage silent electrical discharge or by electrolysis at low-voltage ─ if
indeed, you did produce trace ozone it would be in any airspace between the alufoil and the plastic container . . . ?
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blogfast25
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The idea that ethyl acetate is being formed here (apart from whether ozone is formed) seems folly to me.
At best ethanol in watery solution may have been oxidised to ethanoic acid. But to form an ester like ethyl acetate, both the alcohol and the
carboxylic acid have to be quite dry and concentrated sulphuric acid needs to be present as a catalyst (Fisher esterification). This is far removed
from the conditions here described.
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Nicodem
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Thread Moved
29-3-2014 at 07:57 |
WGTR
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The sulfuric acid helps drive the reaction to completion. As blogfast25 says, there's too much water in the reaction,
so the equillibrium is on the left side of the equation:
C2H5OH + HAc <--> C2H5Ac + H2O
Ozone oxidation of ethanol seems to be very inefficient, according to the reference that I posted earlier. It does work,
but a catalyst is needed (ferrous or manganese (II)), and not all of the ozone reacts. One thing it suggested was a
two-step process, where manganese(II) sulfate is oxidized to manganese(III) with ozone, which is then heated with
ethanol. The solution goes from clear to dark red as manganese(III) is formed, and then dark red to clear as the alcohol
reforms manganese(II). This gives a visual indication of the reaction's progress. It may help to do this reaction in dilute
sulfuric acid to keep the manganese in solution.
Those aren't the only salts that work. Some of them are listed in the reference. Their effects differ depending on how
strong an oxidizer they are, and if they are oxidizable by ozone or hydrogen peroxide.
The idea is for the ozone (etc) to oxidize the catalyst, which in turn oxidizes the alcohol. You can try different salts and
reaction conditions to see what happens if you like.
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