[kioplo]

Okay, so recently I decided to try to extract iodine from the topical tincture solution you can buy at the store, i did one bottle just as a test, i used hydrogen peroxide and HCl mixed into the tincture, the I2 came out of solution and I was able to collect it.  I then decided to do it again with the rest of the bottles i had, but i did not have enough hydrogen peroxide, so i decided to use bleach instead.  I did the same process, i diluted the tincture solution with an equal amount of water, and added the HCl and NaOCl, the I2 immediately came out of solution, i was getting ready to dilute the contents of the bottle when all of the sudden the I2 dissapeared back into solution.  I figured I had lost equillibrium so I tested the pH and tried adding different amounts of reagent to reform the I2 crystals, but this was useless I was unable to get them back out of solution.

Soooo, my question is, is my project completely unsalvagable?....what can i do to try and get the I2 out of solution?....also it would be nice if someone could give me more insight into the reactions that are taking place and how they get the I2 out of solution.

                               Thanks,
                                             Jon

[jdurg]

When you mixed NaOCl with HCl you created chlorine gas in your solution.  Immediately, the chlorine gas oxidized the iodide (I-) ions into elemental iodine which you probably saw ppt out of solution.  However, Iodine and Iodide readily form I3(-) which is highly soluble.  So what happened is that the excess I- in solution caused your I2 to dissolve once more.

[kioplo]

is there anything i can do to get I2 out of the solution i have now?

[Kenichi]

I recently encountered the same problem. Like yours Kioplo, my crystals formed but then dissolved again.   I then added about 30 mL of Hydrogen Peroxide and the mixed.  The crystals formed once again and stayed.  Before filtering the solution let it sit for a while. I found that i tried too early to filter it and the crystals dissolved again in the solution (while I was pouring it) and they reformed in the container below the filter.
Hope this can be of some help.

[Mitch]

Boil the solution under a watchglass of ice. Your iodine should form nice crystals on the bottom of it.