Re: Why do you need to put a bung on a conical flask of Lithium Hydroxide in aq

Why do you have to put a bung ("stopper" to us Yanks) on anything?

Usually it's because you don't want the thing to run all over the benchtop
if you knock it over. Secondarily, even in aqueous solution strong bases
are hygroscopic, so if you don't want the concentration of your solution to
diminish you'd better stopper it TIGHTLY. Otherwise it will pick up water 
from the air; over a few weeks in a humid environment, you can actually
observe the volume of concentrated solutions growing.

                                                Dan Berger
                                                Chemist and MadSci Administrator