I read an MSDS on N2O that noted a hazardous reaction between NaOH (and KOH) and N2O (see https://www.google.com/url?sa=t&source=web&rct=j&... ). Now , a MSDS is generally not good source on points of chemistry, but upon
attempting this reaction twice, it is unlikely I will repeat. The reaction is best described even with small amounts as dangerously exothermic. My
speculation on how this warning became worthy of recognition was most likely a warehouse fire with evident fireworks observed.
I first place some 3% H2O2 (infused with N2O) and N2O gas itself, in a container in the microwave and heated to release any dissolved N2O. I then
carefully drained off the fluid leaving a moist container with N2O and some O2 and inserted dry NaOH. On my first attempt employing all glassware
while heating the mixture in a microwave, the porcelain disk containing the NaOH in an atmosphere of N2O and water vapor did not crack, it shattered
at the first sign of a yellow spark. The second attempt in a microwave oven produced significant yellow fireworks with now a plastic container
subsequently catching on fire. The white salt created seemed resistance to dissolving in NaOCl.
Speculation on possible reaction paths: As noted in the opening thread above, to quote:
"A side comment I found interesting is how N2O in N2/O2 mixture is converted into NO in a microwave..."
So one might expect:
2 NaOH + NO + NO2 → 2 NaNO2 + H2O (reference http://www.allreactions.com/index.php/group-1a/natrium/sodiu... but for cold NaOH )
but not readily as the rate controlling step is dependent on the formation of the reactive nitrogen species via the microwave radiation to produce the
required NO:
N(2D,2P) + O2 → NO + O (reference, p. 144 at http://books.google.com/books?id=8MXX01Qw_G0C&pg=PA143&a... )
Other possible paths, both exothermic, include (source: see http://connection.ebscohost.com/c/articles/7644257/gas-phase... or http://scitation.aip.org/content/aip/journal/jcp/85/10/10.10... ):
NaO + N2O = Na + N2 + O2
NaO + N2O = NaO2 + N2
where any formed Sodium metal would rapidly and violently react with water vapor. I also found this article presented at the 14th International
Conference on the Properties of Water and Steam in Kyoto titled "The role of water in N2O anion dissociation and reaction rates of N2O with hydrated
electrons in high temperature water" by Kenji Takahashi et al. available at https://www.google.com/url?sa=t&source=web&rct=j&... also informative.
With respect to Sodium peroxide, per Wikipedia (see http://en.m.wikipedia.org/wiki/Na2O2 ) and http://www.allreactions.com/index.php/group-1a/natrium/sodiu... :
2 Na2O + O2 → 2 Na2O2 (or 4 NaO between 250—350° С, under pressure)
and would assume (not certain) the Na2O or the NaO could be derived under these particular reaction conditions from the NaOH (perhaps 2NaOH + N2O →
2NaO + H2O + N2 in hot water vapor, or via the direct action of H2O2, formed by active oxygen on decomposition of N2O, with NaOH) to be able to accept
the above reaction path (which appears to only require strong heating of NaOH in the presence N2O and possibly O2, and does account for the
'fireworks' effect).
[Edited on 13-8-2014 by AJKOER] |
