[JMiller]

Hello!

Does anyone know if Acetone and Ethanol form an azeotrope?
I have a 60/40% Acetone/Ethanol solution that I am trying to fractionally distill. 
However, the first product comes over at 60-61C, even though Acetone's BP is 56.53, and Ethanol's is 78.4. 
Tried it a couple of times, making sure everything was 100% on each run, with same result, worried that I am NOT getting very clean acetone.
Having said that, I have found NO info about whether the two form an azeotrope on any charts.

thanks for your *delete me*

Jeff

[KritikalMass]

Acetone is miscible in water and so is ethanol, and each form an azeotrope when mixed with water. As a result, I am going to say that yes, they form an azeotrope with one another because if they are both miscible in water then they must both be miscible with each other.

However, I did find this on Wikipedia:

"Miscibility of two materials is often determined optically. When the two miscible liquids are combined, the resulting liquid is clear. If the mixture is cloudy the two materials are immiscible."

[Borek]

Wiki - while a great source - can be misleading. That's the case. Just because some mixture is clear doesn't mean liquids are miscible.

[KritikalMass]

Wiki - while a great source - can be misleading. That's the case. Just because some mixture is clear doesn't mean liquids are miscible.

How about the rest of my reasoning? Would it be true that if two liquids are each miscible with water than they would be miscible with each other? 

[Borek]

No. I can't think of an example now, but it doesn't have to work this way in general. But as a rule of thumb it should be OK.

[Markov]

Hi there,
It might not be easy to get efficient separation of these two by simple distillation.

Acetone/ethanol is not listed in this azeotrope databank:
http://eweb.chemeng.ed.ac.uk/chemeng/azeotrope_bank.html

You might want to ask yourself: What is the purpose here?

Is this a study case only? Then you may have more fun if you choose another mixture to study, i.e. with a known and useful azeotrope.
 
Are you interested in the distillate of acetone for e.g. cleaning of cooling bath? Then fine- you may get something useful out of it. Remember that if the system contains water it is likely to affect the system, too. Drying prior to distillation (with e.g CaCl2) may be advisable. It will be very messy though. Consider calculating the cost of goods saved vs expected labor.

Are you interested in the ethanol e.g for drinking? Then forgetaboutit, it will be highly inefficient and likely you will never be able to get rid of enough acetone. 

Good luck!

[JMiller]

excellent, thanks so much for your replies!  yes, it was just a study case, and one I learned a lot from thanks to you guys.  cheers, great forum btw!