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Author: Subject: Storage of LiAlH4
Eisenpanzer432
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[*] posted on 17-6-2018 at 16:03
Storage of LiAlH4


I stored about 50g LiAlH4 which I received wrapped in 10-15 plastic bags in a mason jar with desiccant packs. After about 2 weeks the top of the jar was bulging, so I burped it, and the bags puffed up really fast. Is this from H2 offgassing somehow? The temp was kept between 15 and 20C with no light exposure.
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woelen
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[*] posted on 19-6-2018 at 23:54


I think that a little moisture was inside the jar, which slowly reacted with the LiAlH4. The desiccant packs also may have contained some water. With LiAlH4 in the jar the vapor pressure of water will have been so low that any water, absorbed by the desiccant, was released again.

With some chemicals, it is best to have them in a jar without anything else. Even desiccants may be nasty sources of water vapor in such cases. Examples are:
- P4O10
- SO2Cl2
- LiAlH4
- NbCl5
For some chemicals there can be pressure buildup in such cases. I had a strongly pressurized container of NbCl5, which on opening released a big cloud of HCl.




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Eisenpanzer432
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[*] posted on 23-6-2018 at 10:36


I tried vacuum sealing it three times with dessicant packs in each layer, and it has started to puff after two days. I will try vacuum sealing again without any dessicant and see if that works.
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