I know it's probably a stupid question, but I can not figure this out. I have a liebig condenser that I usually use for distillation with a Kjeldahl bulb, which makes it easy to attach to a flask because the bulb has a stopper on both ends?

Now I have an experiment that calls for reflux heating, where the condenser needs to be held vertically over the flask. One end of the condenser is a cork-fit opening, and the other end is a spout. The flask also has a cork-fit opening.


1 Answer 1


Maybe I don't understand your question well, but often in the lab when we do reflux heating, we don't really attach the liebig condenser.

You fix the flask using a clamp. And gravity holds the liebig condenser into place. You can put a clamp around it to hold it straight but you'd better not tighten it too much because these things are fragile.

I hope it helps you :)

If it's not clear maybe it would be easier to answer if you posted pictures of your glassware!

  • $\begingroup$ Those Keck-clips are awesome :) $\endgroup$
    – Jori
    May 2, 2015 at 9:19
  • $\begingroup$ Thanks for your help, but I don't think I can just let gravity hold the condenser in place because my glassware does not have ground-glass joints. I believe I found the fix, it is a 14mm-18mm male-to-male glass adapter. Apparently they are meant more for the cannabis market, but I think it will serve my purpose. $\endgroup$
    – dfghj
    May 5, 2015 at 23:27
  • $\begingroup$ I think that a PTFE (teflon) sleave is a good idea with ground glass joints as it stops the glass joints getting stuck. Of all things in my lab the most dangerous object is the humble liebig condensor. Take very great care when pushing a glass tube through a rubber bung or a cork. Also take great care when attaching rubber hoses to a glass tube (like the water connections on a liebig). The modern Quickfit liebig with screw on water connections is one of the greatest safety improvements in organic chemistry in my opinion. $\endgroup$ Apr 15, 2018 at 20:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.