# Do xenon di- and tetrafluorides react with glass?

A question came in my test asking which of the compounds are not stored in glass. The answers were $$\ce{HF},$$ $$\ce{XeF6},$$ $$\ce{XeF4},$$ $$\ce{XeF2}$$.

I know about $$\ce{HF}$$ and $$\ce{XeF6},$$ but not about the other two. As far as I remember, xenon does not have any oxide or oxyfluoride in the $$+4$$ and $$+2$$ oxidation state.

Is the given answer correct, and if so, what are the reactions involved?

• Interestingly, when a professor brought a small amount of $\ce{XeF2}$ into the lecture hall to pass around as a demonstration, I recall it being in a glass vial. However, if it was he could have just filled it into a glass one from a plastic one to prevent the plastic smell from obstructing the $\ce{XeF2}$ smell.
– Jan
Dec 19 '18 at 14:34
• @Jan - it isn't like adding some HF to a glass bottle will instantly dissolve the glass. Similarly, the glass will probably last just fine with a bit of gas in it. Dec 19 '18 at 16:41
• @JonCuster XeF2 isn't gas in r.t.. Also it shouldn't attack glass unless there's been for ex. significant hydrolysis or high temp. Dec 19 '18 at 23:37

## 1 Answer

Firstly I'll note the title and the body of the question ask slightly different things; just because substance X doesn't react with glass doesn't mean substance X should be stored in glass.

As far as I can tell $$\ce{XeF4}$$ and $$\ce{XeF2}$$ don't react with glass, at least not quickly. Greenwood and Earnshaw says of $$\ce{XeF6}$$, when comparing it with the other two fluorides, "the compound cannot be handled in glass or quartz because of a stepwise reaction" (see Why is xenon hexafluoride not stored in glass?). Housecroft and Sharpe says "At 298K $$\ce{XeF6}$$ reacts with silica (preventing the handling of $$\ce{XeF6}$$ in silica apparatus) ... while $$\ce{XeF2}$$ and $$\ce{XeF4}$$ do so only when heated". So it appears the lower halides do not react with glass at s.t.p.

Whether they should be stored in glass depends, I am guessing, upon the importance of hydrolysis by water in the atmosphere; this forms HF which will attack the glass. I can't answer this - I only mix compounds in computers.

Note an oxide of Xenon is known in the +4 state (see https://en.wikipedia.org/wiki/Xenon_dioxide) as is at least one oxyfluoride (https://en.wikipedia.org/wiki/Xenon_oxydifluoride)