Sciencemadness Discussion Board

KOH vs glass bottles

nerdalert226 - 9-5-2012 at 16:48

Would a .9 molar solution of KOH be a danger to my Borosilicate amber glass bottles?

Pyridinium - 9-5-2012 at 17:04

After a while, any strongly alkaline solution will attack the glass and probably freeze shut the glass joint. It's just a matter of how long. KOH doesn't seem to attack glass as quickly, though.

This question was debated in
http://www.sciencemadness.org/talk/viewthread.php?tid=15633

from my own experience I've found rings of white (devitrification) in glass just from leaving sodium carbonate solutions in it for a few weeks. You probably wouldn't notice that looking through an amber bottle, though.


mycotheologist - 10-5-2012 at 12:19

Are you talking about storing KOH solution in glass bottles? If so, I'd say HDPE containers is a better option. I know that HDPE resists concentrated NH3 solutions very well and I assume the same goes for alkali metal hydroxides. I've had a HDPE bottle of LiOH solution in my lab for a couple of weeks now and there are no signs of a reaction occurring.

[Edited on 10-5-2012 by mycotheologist]

GreenD - 10-5-2012 at 12:23

a .9 molar should be fine for glass itself, its not going to seep through it or deform it dramatically, but it will interact with the surface.

The only problem is do not use it with a glass-joint stoppered bottle.

I was dealing with a highly basic separation in a funnel, didn't wash the glass stopper well and now I can't even use the dang thing until I get a torch and flame heat the glass, which itself is a bad idea.