lacrima97 - 13-4-2006 at 06:21
I was thinking something the other day. The reaction goes
Hexamine+Peroxide---->Hmtd+Ammonia
Now, the main reason that citric acid is used in this reaction is becuase it plays a role in reacting with the ammonia, and shifting the equilibrium
over a bit. (at least this is what I understand).
So anyway, A few days back, I added a considerable amount of 27% H2O2, and hexamine in the same flask. The vessel got hot, maybe around 50C. I come
back a day later, and there are still bubbles coming up. I am thinking that these bubbles are NH3 bubbles. (there is a light precipitate in the
bottom of the flask (hmtd)).
If the stopper is put on the top, and it is shaken, alot of gas is made, and the stopper is blown off. It smells of windex, so it is ammonia.
So, what I am thinking is that if you had a filtering flask, and hooked up a vacuum to it, wouldn't this pretty much work in place of citric or
sulfuric acid? It might be slow, but wouldnt it probably work ok? I mean, the point of the acids is to move the equilibrium, so I am thinking that
the vacuum would remove the NH3. Any ideas? 
rot - 13-4-2006 at 06:41
Don't think that's the way it works. the acid is not to remove the NH3, it acts as a catalyst for the hexamine + h2o2 reaction, just like with TCAP
DeAdFX - 13-4-2006 at 14:08
If you believe that the gas is ammonia then collect as much of the unknown gas as possible and do a titration. On second thought test the ph first
using litmus paper. If it isn't basic then the gas is obviously not ammonia. If basic do a titration.
[Edited on 13-4-2006 by DeAdFX]
Marvin - 13-4-2006 at 15:14
The acid is only catalyctic for acetone, you need molar amounts for hexamine.
Think logically about the gas.
Ammonia - very very soluable in water.
Hydrogen peroxide - tends to evolve oxygen on standing.
Test the gas with a lighted splint.
Deceitful_Frank - 13-4-2006 at 15:57
Or even a smouldering one!
Canuck - 27-5-2006 at 22:59
lit splint won't do anything but glow brighter.. smouldering is what you want.
I'd be careful doing this around HMTD.. actually I wouldn't be caught doing this in the same room for safetys sake.
Sorry.. I have to mention the obvious.