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Chemistry Forums for Students => Organic Chemistry Forum => Organic Chemistry Forum for Graduate Students and Professionals => Topic started by: ken2_lao on March 13, 2009, 07:43:30 AM

Title: vacuum distillation
Post by: ken2_lao on March 13, 2009, 07:43:30 AM

Hey,
   I was vacuum distillating some benzoyl chloride. The weird part is the distillate that is coming out of the condenser keeps moving back up, it won't go down the freaking flask. Any suggestions? ???

Title: Re: vacuum distillation
Post by: P on March 13, 2009, 08:29:00 AM

Put a cold trap arround the collection vessel. If you are collecting into a test tube, then submerge it in some IPA that has a load of dry ice in it, or use and ice bath - but the CO2 in IPA will be colder.  The temperature gradient helps pull the vapours down via a pressure drop and also keeps the condensed product liquid.

Title: Re: vacuum distillation
Post by: ken2_lao on March 27, 2009, 07:00:02 AM

Wow, sorry for not replying asap. Thanks a lot!  Unfortunately, we don't have dry ice available... I'll try some salt-ice baths instead :)

Title: Re: vacuum distillation
Post by: P on March 31, 2009, 06:50:35 AM

Let us know if it works.   :)