I've got some old nitromethane, supposed to be pure, but the bottle was half full and I suspect this stuff has leached water from the air over time.
How would you dry NM?
Molecular sieve is one possibility.
I have little experience with it. How is it ideally used?
And since it is also expensive, I also thought of CaCl2 and Magnesium sulfate.
It seems like CaCl2 is often contaminated with C(OH)2, which creates explosive nitronates with NM. (I did not yet understand the chemistry behind
it...)
Magnesium sulfate would be another solution.
But how do I use them properly?
Wouldn't the desiccant swallow not only the water but the NM too?
Do desiccant and NM have to be in direct contact, or is it possible to use a common exsiccator or some similar device?Loptr - 22-4-2015 at 15:51
You can use neutral dessicants, so magnesium sulfate would work. I thinking is normally distilled to purify it, either that, or cooling it below its
melting point and collecting the solid, followed by distillation.
Why do you need it so dry? Is it really than hygroscopic?
As you seen in the screenshot of the above link, you could also use 4A sieves, or other filterable desiccants.
[Edited on 27-4-2015 by Loptr]Gargamel - 3-5-2015 at 06:40
Thank you. I read through that page some times before.
I'll try molecular sieve. I just sought something cheaper, Magnesium sulfate is dirt cheap in comparison.
My NM does not need to be superpure, but water free. Fantasma4500 - 3-5-2015 at 09:21
you could also try sodium sulfate, it should be a decently aggressive dessicant.. it could be added to the liquid, whereafter liquid is then decanted
off, or you could just place the dessicant in a plastic box and put the NM in a beaker ontop of the dessicant..
you could also fill whatever dessicant into a metal can and place it next to the cup of NM in a plastic box, or bag etc
the idea with this is that you may wanna use the same dessicant several times, calcium chloride doesnt etch aluminium up much, so you could take the
whole can and heat to dryness, not having to deal with getting the dessicant back out, simply placing the dessicant back in the box
