Luke Lively
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Miscibility between saturated H2O and Acetone
Hi all, apologies if I posted in the wrong section.
Quick question, would acetone mix with H2O saturated with NaOH?
Would acetone mix with partially saturated H2O?
Thanks.
[Edited on 9-6-2016 by Luke Lively]
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gdflp
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You would get a flask full of crap. Conc. NaOH would catalyze an aldol condensation of acetone with itself, forming a tarry mess quite rapidly.
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Luke Lively
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That's terrible news. Thanks for your help gdflp.
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brubei
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aldolisaton of acetone needs heat, also excess of water displace the equilibria to hydrolysis. Then if your reaction is faster than the degradation of
acetone and easy to purify, it can be performed with only little trouble
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Luke Lively
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Assuming that I can work before the Aldolization takes place, would the acetone be miscible with the saturated H2O?
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aga
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Quote: Originally posted by gdflp  | | You would get a flask full of crap. Conc. NaOH would catalyze an aldol condensation of acetone with itself, forming a tarry mess quite rapidly.
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Now there is a proposal i can readily test.
What would the tarry mess consist of ?
Some kind of polymeric form of acetone ?
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Firmware21
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͖̻̲̪̲̙͘ͅe͙͕͙̙̤̤̫̒ͩͣ̅̊̍̉͒ͬ́͟ͅs͈̬̮̥̻͂ͥͨ̂ͮͨ͒́͠ !!!
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Most probably, as a linear "poly aldol" ?
I happen to have a special erlen in which i tried that reaction. 2 whole years of reaction time...
I'll post a picture someday.
And yes, it forms 2 layers when mixed with a saturated NaOH. 9 molar NaOH is what I used.
[Edited on 9-6-2016 by Firmware21]
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Nicodem
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Thread Moved
10-6-2016 at 10:23 |
PHILOU Zrealone
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| Quote: Originally posted by aga | | Quote: Originally posted by gdflp | | You would get a flask full of crap. Conc. NaOH would catalyze an aldol condensation of acetone with itself, forming a tarry mess quite rapidly.
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Now there is a proposal i can readily test.
What would the tarry mess consist of ?
Some kind of polymeric form of acetone ? |
CH3-CO-CH3 + O=C(-CH3)2 --> CH3-CO-CH2-C(-OH)(-CH3)2
CH3-CO-CH2-C(-OH)(-CH3)2 --> CH3-CO-CH=C(-CH3)2 (mesityl oxyde) + H2O
(CH3-)2C=CH-CO-CH3 + O=C(-CH3)2 --> (CH3-)2C=CH-CO-CH2-C(-OH)(-CH3)2
(CH3-)2C=CH-CO-CH2-C(-OH)(-CH3)2 --> (CH3-)2C=CH-CO-CH=C(-CH3)2 (phorone) + H2O
3 CH3-CO-CH3 --> C6H3(-CH3)3 (mesitylene) + 3 H2O
...
Each C=O could react with a CH3 close to a C=O and also you could get polymerization, cyclization, crosslinking from the conjugated C=C / C=O or C=C /
C=C systems.
Thus yielding upon time orange, brown, black tarry-waxy-sticky compounds of undefined structure...
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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Firmware21
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͖̻̲̪̲̙͘ͅe͙͕͙̙̤̤̫̒ͩͣ̅̊̍̉͒ͬ́͟ͅs͈̬̮̥̻͂ͥͨ̂ͮͨ͒́͠ !!!
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And it should look like this after 2 years... 
 
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zhiang0113
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That kinda reminds me of my recent attempt to hydrolyse paracetamol into 4-aminophenol... I had no idea the latter oxidised so quickly (even under
acidic conditions). Left some horrible dark green-brown sticky mess clinging to the sides of my beaker, which looked pretty much like mold gone crazy.
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aga
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Yesterday i put 2g NaOH into one beaker of 20g acetone and 2ml conc H2SO4 into another.
The basic flavour formed 2 layers quite quickly, the acidic one didn't do much at all.
How fast is 'quite quickly' ?
Edit:
Googling revealed the 'Aldol Condensation' which says it should form mesityl oxide from two acetone molecules and produce some water, either by an
Enolate route (basic) or Enol route (acidic).
Further reaction of mesityl oxide with another acetone to give isophorone in a ' Michael addition' appears to require some kind of catalyst.
Hey ! Yesterday evening the wiki page mentioned that, yet today the page seems to be a lot shorter and with less details !
[Edited on 12-6-2016 by aga]
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