Monoamine - 9-8-2021 at 15:28
While some gases are cheap enough to make that it's fine to just make them as needed while others can be "collected" by passing them through a liquid
that they dissolve in, there are of course also times where it would be nice to be able to store and collect a gas so it isn't wasted.
The specific example I have in mind is bromomethane (BrCH3). It just seems really handy since it could be used for many cool experiments
like making single carbon Grignard reagents, aromatic methylations, ethers, etc...
But having to use up a bunch of HBr to make it from methanol every time is not only a waste of HBr, but unless the BrCH3 reacts almost
instantaneously, you probably need to generate a huge amount to complete the reaction.
Of course gas made in glassware can't be stored in a gas cylinder, since the pressure required would probably make the glass explode.
So I'm kind of hoping someone might know of a viable method for doing this?
Or are there any techniques to "recycle" gas that didn't react with the content of the solution it was passed through? Instead of wasting it into
"thin air" are there ways to keep cycling it through the solution until enough has reacted?
Any tips would be greatly appreciated!
Thanks!
Oxy - 9-8-2021 at 20:42
You can use low temperature to liquefy the gas and store it then in a gas cylinder.
Regarding bromomethane - why don't you make iodomethane? It's a liquid in normal conditions and allows you to do all the things you want from MeBr in
more convenient manner.
[Edited on 10-8-2021 by Oxy]