Sciencemadness Discussion Board

Iodine trichloride and Al

Zinc - 24-5-2006 at 08:41

I was thinking if a slurry of ICl3 and Al could be used as a "flash slurry" since I know that Al react violently with I2 and Cl2?
The equation would be:
3ICl3+4Al---AlI3+3AlCl3

Nerro - 24-5-2006 at 08:46

Something tells me the reactionproducts could be a lot more complicated than that. Also ICl3 dimerizes to form solid crystals of I2Cl6 which slowly decompose to form Cl2 and ICl.

To mix the reagents would be a perilous endeavour to put it gently.

DeAdFX - 24-5-2006 at 16:32

Do you honestly have to start a thread about every halogen/oxygen containing compound + aluminum?

woelen - 25-5-2006 at 12:59

I have done a similar experiment with KICl4, which I made from KIO3 and HCl. I mixed the dry solid with Mg-powder. No reaction occurred. When I added a drop of water, a violent reactoin started and a purple cloud of I2 was formed.

KICl4 is not hygroscopic, so mixing with Mg-powder can be done. I'm quite sure that the reaction with Al-powder will be quite similar, but I did not try it.
KICl4 is efflorescent though. It can be regarded as KCl.ICl3 and it slowly gives off ICl3, when not stored in a tightly sealed container.

nitro-genes - 26-5-2006 at 04:07

Quote:
Originally posted by woelen
I have done a similar experiment with KICl4, which I made from KIO3 and HCl. I mixed the dry solid with Mg-powder. No reaction occurred. When I added a drop of water, a violent reactoin started and a purple cloud of I2 was formed.


Could it be that the reaction is started with addition of a little water because free chlorine/iodine is formed together with hydrogen? Hydrogen/chlorine mixtures are known to be initiated by photons emitted from artificial light and magnesium produces hydrogen quite easily with water, especially at higher temperatures. So, in this respect mixing with aluminium may be quite different...
I tried mixing aluminium powder (400-500 mesh) once with powdered iodine, expecting a vigorous reaction, I was quite surprised it didn't even sustain it's own reaction upon ignition. Never tried with magnesium though...

[Edited on 26-5-2006 by nitro-genes]

woelen - 26-5-2006 at 11:46

I don't know why the water starts the reaction, but this phenomenon is quite well known. A similar effect exists for AgNO3+Mg. A powdered mix of these, when absolutely dry is stable, but a small drop of water sets of the mix and a REALLY violent reaction starts, with a bright white flash, and molten silver being sprayed around.
When iodine and magnesium are mixed, and water is added, then also a very violent reaction starts, but the dry parts do not react. Apparently the water is needed for that reaction. Here is a page, describing that reaction, which I made:

http://woelen.scheikunde.net/science/chem/exps/mg+iodine/index.html

The reaction between KICl4 and Mg is quite similar, but more violent.

[Edited on 26-5-06 by woelen]

Reactions

MadHatter - 27-5-2006 at 00:37

Yes, much like my accident with Armstrong's mixture, a chemist I know was without
eyebrows for a while because of AgNO3/Mg/H2O.