Interesting experiment with interhalogens

[woelen]

I did a nice experiment, in which I made two interhalogen compounds. Making one of them react with magnesium metal also is quite spectacular. I did the experiment last weekend and below follows a report with pictures of the experiment:

 

http://81.207.88.128/science/chem/exps/Cl+I/index.html

 

If you want to perform the experiment yourself, be very careful. Carefully read the info on safety in the experiment's description.

 

Have fun, but keep things safe and healthy!

[folder]

Very interesting. It's curious how ICl is similar to bromine.

[jdurg]

Logically it would make sense, however. Since bromine is between chlorine and iodine, it's stronger than iodine but weaker than chlorine. The combination of iodine and chlorine results in a compound with a high enough molecular mass to be a liquid, while it's slightly weaker than chlorine but stronger than iodine.

[woelen]

Indeed, the first person, who actually made elemental bromine, thought that what he had made was iodine (I) chloride, which was known at that time already. So, the person, who officially is called the discoverer of bromine (Antoine Je´rome Balard) was not the first one to prepare it (in 1826). Years before, Justus von Liebig, a German chemist, had prepared elemental bromine.

 

Jdurg's argument that the interhalogens form compounds, with properties intermediate between the properties of the parent halogens, only holds for Cl, Br, I. Interhalogen compounds, containing fluorine (e.g. ClF3, IF7) are colorless gases and do not resemble the parent halogens. The element fluorine is quite an anomaly in the set of halogens anyway.

 

BTW, I made a little more of the ICl (appr. 1 ml) and kept it in a small vial, but this stuff is really corrosive. It has eaten a hard plastic cap, just within a few days. I "disposed of" the stuff now, by reacting the whole lot with fine aluminium powder, which gave a beautiful red plume of gas, almost like my avatar (just slightly more purple), and a little white smoke, again only after some water was added. The red gas probably is a mix of gaseous I2 and ICl. Quite spectacular....