Sciencemadness Discussion Board

drying tube... odd configuration

GreenD - 3-4-2013 at 09:38

Hey, I've only worked with drying tubes once before and they were simple and straight like this:

http://www.americanlabware.com/images/A86.jpg

Now they seem to be popularly like this:
http://www.chem.cuhk.edu.hk/rbs6_photos/Expt12_photo/DSCN980...

Why? I'm assuming I attach them to the same spot - atop the condensor in a refluxing reaction, but now I have to plug both holes with cotton.

elementcollector1 - 3-4-2013 at 09:44

I have one that's a full 180 degree turn, with only one ground glass joint.
I think it varies from drying tube to drying tube - all work just as well.

Hexavalent - 3-4-2013 at 13:16

Yes, those are common too. Personally, I use a Kjeldahl bulb packed with anhydrous CaCl2 and plugged with ordinary cotton wool for a drying tube, which seems to work adequately.

GreenD - 3-4-2013 at 23:24

I don't get it, whats the point of the curvature

kavu - 4-4-2013 at 01:04

In case the cotton plug on the bottom fails partly hydrated CaCl2 will fall into your apparatus. This might be problematic in some cases. Also really high apparatuses are easier to tip over and break.