Eisenpanzer432 - 17-6-2018 at 16:03
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.
woelen - 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.
Eisenpanzer432 - 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.