thysonsacclaim
Harmless
Posts: 5
Registered: 6-7-2009
Member Is Offline
Mood: No Mood
|
|
An azeotrope?
I was in lab not too long ago finishing and we were just finishing a reflux process when my professor started talking about how we should clean our
condensers.
We were told to rinse out the inside of our condensers with DI water and then squirt them with acetone. She told us that "when water and acetone are
mixed, it "forms a ______ and makes the evaporation of the mixture faster than either of the two solvents on their own."
Unfortunately, I didn't hear the word she said because a clumsy girl dropped a condenser at the same time that was being said. Now that it is summer,
the professor is gone and I cannot ask her. I could not think of anything else that fits besides azeotrope, but that has to do with boiling and not
evaporation.
Any ideas? Thanks.
Scientia est potentia
|
|
|
Arrhenius
Hazard to Others
Posts: 282
Registered: 17-8-2008
Location: US & A
Member Is Offline
Mood: Stochastic
|
|
Acetone does form a nice azeotrope with water, and your glassware dries quickly. It's also exceptionally good at dissolving whatever organic residues
might be left in your condensor. This is likely the word you didn't hear 
funny story of the lab mate though!
|
|
|
JohnWW
International Hazard
Posts: 2849
Registered: 27-7-2004
Location: New Zealand
Member Is Offline
Mood: No Mood
|
|
Actually, acetone and water form NO azeotrope; the series of mixtures instead has a point-of-inflection in the boiling-point versus
composition curve, which I suppose is a close approach to azeotropy though. See:
http://en.wikipedia.org/wiki/Azeotrope_(data)
http://www.solvent--recycling.com/azeotrope_1.html
http://www.eng-tips.com/viewthread.cfm?qid=139240&page=1...
http://www.mtholyoke.edu/~arokullo/independent.doc
Perry's Chemical Engineers' Handbook chapter 13, which deals with binary and ternary liquid mixtures, azeotropes, and distillation, does not seem to
have anything on acetone-water mixtures; but the phase diagram and details of the water-acetone system should be in the International Critical Tables,
Handbook Of Chemistry & Physics, Taschenbuch Der Chemie, and the Lexikon Der Chemie, and Lange's Handbook Of Chemistry in the References section.
Separation of water and acetone would be of industrial interest, in recycling acetone used in solvent extraction processes which result in water
getting into it.
|
|
|
Nicodem
|
Thread Moved
19-7-2009 at 22:15 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
