Sciencemadness Discussion Board

Iodine Extraction from a Aqueous Solution

Blind Angel - 4-3-2004 at 18:47

I just bought 1 liter of Iodine in aqueous solution @ 0.1M (for 90$CAN) ans i was wondering if it was possible to extract it to have crystal iodine, or if i'm better to leave it in solution. I know that i can't simply boil of the liquid or let it evaporate due to Iodine low sublimation point.

I would also like to know if 90$ for 12,6g (i suppose) of iodine is a good price.

Mumbles - 4-3-2004 at 19:00

There is always the boil the solution with cold finger method. Basically just fill a bowl with ice and place over the boiling solution to collect the crystals.

That price is pretty horrible. One can buy a pound for C$140 from Canada. The guy seemed very nice and helpful when I procured something else from him. It's roughly C$7.15 a gram for what you have. I've seen it going for C$7 an ounce. This was not a bad purchase by all means though. If you want to mass produce it I would recomend a better source however.

90 BUCKS FOR TWELVE GRAMS!!!

Hermes_Trismegistus - 4-3-2004 at 23:55

Quote:
Originally posted by Blind Angel
I just bought 1 liter of Iodine in aqueous solution @ 0.1M (for 90$CAN) ans i was wondering if it was possible to extract it to have crystal iodine, or if i'm better to leave it in solution. I know that i can't simply boil of the liquid or let it evaporate due to Iodine low sublimation point.

I would also like to know if 90$ for 12,6g (i suppose) of iodine is a good price.



Are you on dope???:P

thunderfvck - 5-3-2004 at 00:29

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=38019...


Shitty. Anyway you can get a refund? I hope you still have your receipt and it hasn't been opened....:P

hodges - 5-3-2004 at 15:44

Al-Chymist sells potassium iodide for $45 a pound. Most of that is iodine, and not too difficult to extract (depending what you are trying to use it for).

fritz - 5-3-2004 at 17:47

add some lye (e.g. NaOH) to your I2-solution. You will get a solution of iodide (and some hypoiodide or iodate). Add some sulfite (or bubble SO2 through the solution) to reduce all hypoiodide/iodate to iodide. Evaporate to dryness. You now have relatively pure iodide. This you may put into a distilling-appartus add some sulfuric acid and MnO2 and heat. What comes over should be pure(of course this is not p.A. quality!!) solid iodine.

Geomancer - 6-3-2004 at 12:04

Fritz, I'm not sure I understand the purpose of adding alkali. Is that the hypoiodite reacts faster? When I make iodine from tincture, I reduce it first (so as to remove excess water and alcohol). I used metals (both zinc dust and aluminum foil/HCl work), but your favorite reagent will probably work.

thefips - 6-3-2004 at 15:25

Just take an organic solvent,which is not soluable in water.Then mix it and let the phases seperate.The organic phase sholud be yellow.This is the colour of the iodine.After another 2 or 3 extractions most of the iodine should be extracted.If you take a solvent with low boiling point,you can easily get the iodine by boiling(or distilling) off the solvent and you get the iodine crystals.If you want very clean iodine,you can heat it and the crystals will grow at cool surfaces.

Blind Angel - 7-3-2004 at 19:04

Sorry if i didn't answer before i was in vacation, anyway, i fear that boiling off the liquid will also sublime the iodine thus lossing a lot of it.

vulture - 8-3-2004 at 13:13

I was distilling a mixture of toluene and I2 today and ALOT of I2 made it's way up to the top of the vigreux column, it's a bitch to separate.

Esplosivo - 29-3-2004 at 08:51

The iodine tincture I obtain contains I2 / KI / EtOH / water. Time ago I extracted Iodine from it. I added KMnO4 solution (acidified) to the tincture so to oxidize the KI to Iodine. The mixture was then heated in a sort of 'cold-finger' apparatus I had made myself. Quite a lot of I2 formed, though if you need somewhat large quantities I suggest you buy it.