Author Topic: Toluene Extraction The Final Frontier  (Read 13484 times)

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geezmeister

  • Guest
Which synth?
« Reply #20 on: January 09, 2004, 12:19:00 PM »
Flask size depends on which synth you are doing, and by what method. The drier push-pull type rP/I2 reaction requires larger flasks because of its tendency to double and expand out of the flask with intense bubble formation;
the long wet reflux rP/I2 does not share those characteristics and can be safely done in a smaller flask.

Shorty is most familiar with hypo reactions done with some form of reflux, and these may be done safely in a smaller flask. I would prefer a 500ml flask for a 30 gm reaction. I tend to wash the reaction fluid and base it in the flask in this synth and the phos acid synth, and prefer to have more room in the flask to do this. 

The Phosphorous Acid synth can be done in a flask similar to that used in the hypo reaction, particularly if the HI is made before adding the pseudo or ephedrine. This synth producea HI very quickly and become very vigorous at that point. A full flask increases the risk of balloon failure or seals leaking at the time one least wants a problem. Aside from that moment, this synth is almost bucolic.


SHORTY

  • Guest
I wouldn't go over half the flask for a reflux
« Reply #21 on: January 09, 2004, 12:50:00 PM »
I have a 17g hypo rxn going right now and the level of the solution is no more than 3/4 of an inch deep.  That's in a 250ml erlenmyer.  I remember reading on some chemistry site a long time ago that when refluxing or distilling the flask should never bee more than half way full.  Not sure why or if its true but i have used that as my "flask size rule" since i started using hypo.

When i first started i was using rp and doing dry rxns and as geez says those require a much larger flask than the hypo or lwr do. 

Those dry rxns are just too unpredictable.  It seemed like every rxn went different than the last.  That's probably where the liter per ounce rule came from since that big of a flask would bee sufficient no matter how wild the rxn got.


LoRE

  • Guest
what is the recomended reation vessel size for
« Reply #22 on: January 10, 2004, 03:09:00 AM »

LoRE

  • Guest
ok i utfse
« Reply #23 on: January 10, 2004, 06:54:00 PM »