Remarks on Making Iodine

Over at My Chemical Journey is a Youtube video showing how to make iodine. It's cute, but I do want to make some comments.

This is a "weekend project" only if you have to track down all the reagents and equipment. As home reactions go, this one is straightforward; as an example of high school chemistry, I'll just call it "cute", as before. However, the chemicals involved must be respected.

Safety first - gloves and safety glasses are essential for this synthesis! Don't just wear goggles on your forehead. The lab coat's a good idea too, but not as important.

KI is probably easiest to get online - I've never seen it in a store (though it's out there). There are other iodine sources, of course, but they probably cost more.

Any strong acid will work as 'proton' source, but some choices are better than others from a practical standpoint. For example, concentrated HCl outside a fume hood is nasty stuff due to its volatility.

Do NOT use bleach as the oxidizer, or your lungs will hate you. Sodium hypochlorite reacts with acid to form chlorine, which, as everyone knows, is a corrosive gas. Of course, if you want a chlorine cloud to go with the iodine...

For those with a power supply, electrolysis may be a more cost-effective method. But that's a whole different story.

Do actually be careful with how much oxidizer you add. Too little oxidizer, and you'll get the triiodide complex (the brown stuff), i.e. no crystals. Too much oxidizer (especially H₂O₂), and you get things like iodate; again, no crystals.

It's probably better to do the reaction somewhere cool, since iodine is also (obviously) volatile. This stuff will also stain plastic, and corrode metal. Use glass. (Teflon might also work.)

The traditional way to purify the product is by sublimation. I've never done this step myself, but it shouldn't be too hard (though it'll require a bit of creativity with respect to equipment).

Last but not the least, the product is not easy to store. Also, be careful with waste disposal. Something to keep in mind.

[Edited]
Did I just call electrons oxidants? Sorry. Fixed.