# How is fluorine gas contained and transported, why aren't the metal cylinder and tube in this video attacked?

I included the GIF below as part of an answer to Can paper burn without oxygen or air?. It was made from the video Fluorine - Periodic Table of Videos.

I noticed that the cylinder containing the fluorine gas "filled up on the roof" in the video looks like it is made out of metal, as is the tube feeding the gas to the combustion sample.

The liquification experiment also shown in the video uses a flexible tube that appears to be plastic.

I know hydrofluoric acid will dissolve gas, but can dry fluorine gas be contained in glass? Since metals, even precious metals are generally attacked by fluorine, how is it stored, and how are the metal cylinder and tube in the video not also consumed?

Incidentally you can look up individual elements on Periodic Table of Videos at http://www.periodicvideos.com/

• Nov 11 '18 at 15:22

Elemental fluorine could be stored in glass at least theoretically. It is not the fluorine that attacks the glass but hydrogen fluoride or I think even more precise something like $$\ce{H2F^+}$$. You could avoid that to some degree by drying the fluorine but the problem is the glass itself. As glass forms a polymer structure of $$\ce{[SiO4]^4-}$$-tetrahedra that join all vertices there has to be a sudden end once there is no more repeating unit added. But that would mean that the outside of a glass surface is all negatively charged (ignoring metal cation additives). Therefore there are many $$\ce{Si-OH}$$ groups on the outside which tend to be acidic. When fluorine reacts with them it will form hydrogen fluoride that will attack the glass.