Sciencemadness Discussion Board

Controlling boiling temp - dean stark

Alovira - 5-11-2012 at 08:58

Hello,

I'm trying to measure the amount of water removed from a reaction using a dean stark trap.

The reagents used have a very close boiling point (10 degrees) and I'm trying to plan the best way to measure the temperature as it enters the dean stark apparatus.

The dean stark trap I have does not have a joint for a thermometer, I've improvised by placing a claisen adaptor on the RBF but the additional glass area is condensing the vapour before it reaches the condenser attached to the dean stark trap.

Other than purchasing a new dean stark trap similar to picture one, or insulating the additional glass, can you suggest an alternative to picture two?

Picture one:


Picture two:
(image borrowed from this board)


Nicodem - 5-11-2012 at 13:34

You need to insulate the path to the Dean-Stark trap or else you will have too much reflux going on before the vapours reach the trap.

I did not understood the part about the boiling points of the reagents and how is this connected with the need to measure the temperature of the vapours. Many factors will influence on how they interfere. What is the calc. logP of these reagents? What is their bp? What concentration? Do they form an azeotrope with other components.