I made cca 10g of iodine yesterday from KI, KIO3 and H2SO4. KIO3 was in little excess. I decant supernatant liquid and wash iodine three times with
distilled water. After that I tried sublimate it on balcony in hot water bath. But this is very very slow method, because water is cold after a while.
Heat it on hot plate isn't possible because on balcony isn't socket. And heat it on hotplate indoor isn't possible too because my girlfriend is very
sensitive to iodine.
So, my question is - in all videos on how to make iodine is that iodine must be resublimed because of impurities. What impurities? I tested water from
washing and no sign of sulfate or iodide, solution was neutral - so it's really necesary resublime it?
And one more question - how do you store iodine? I have small bottle from brown glass with plastic cap which seems good for this purpose. This bottle
I plan place in to the plastic bag.
[Edited on 8-12-2019 by Bedlasky]elementcollector1 - 8-12-2019 at 09:11
Where's your sublimation surface? Could do with some additional cooling.
I personally store all my halogens in sealed ampoules immediately after synthesis - it's the one thing they can't seem to find a way to escape from.Bedlasky - 8-12-2019 at 10:24
Sublimation surface is bottom of flask with cold water.diddi - 8-12-2019 at 14:18
as elementcollector says, ampoules are great for display purposes. i do have some I2 stored in double glass GG reagent jars in the freezer also which
has proved fine also. Br2 will store in a freezer also i found draculic acid69 - 8-12-2019 at 19:09
One of uc235's YouTube videos shows his PFA bottle of frozen bromine.apparently PFA bottles can safely store bromine.also keeping it as a solid sounds
like the best way to store it besides ampouling it.also get an extension cord for the balconySulaiman - 8-12-2019 at 20:48
You could use a candle as a heat source for your balcony ?
but an extension cord would be more practical.
I've not ampuled iodine, but I've also not found a completely iodine-proof bottle top
A little iodine vapour goes a long way ... literally
and being a halogen it can corrode steel and many other metals with ease.
[Edited on 9-12-2019 by Sulaiman]Herr Haber - 9-12-2019 at 04:18
Away from everything else !
Regular HDPE is enough to store iodine. My last iodine purchase was stored with the invoice rolled around the bottle.
Nothing else got stained but the invoice is unreadable. Fery - 9-12-2019 at 06:34
Few layers of aluminium foil wrapped around the cap and replaced before corroded throughout (small amounts of escaping halogen react with Al and do
not travel further).
Bottle of Br2 even inside a can surrounded by bags of vermiculite and closed with a lid (a bag below the bottom of bottle is not visible here) - to
prevent breaking of glass by some mechanical accident.
The most safe storage is sealed glass ampule but once opened you can't close it as easily as bottle. And I need to open them more frequently than
once.
If you allow halogen vapors to escape, hasta la vista nearby electronics / metal surfaces... I agree with Sulaiman: no completely iodine-proof bottle
cap.Ubya - 9-12-2019 at 09:35
i store my sublimated iodine (about 1 gram right now) in a vial, in my freezer. storing everything that evaporates or sublimes easily and can escape
containers is best stored at the coldest possible temperature. storing iodine at -20°C lowers its vapor pressure by 2 orders of magnitude versus
ambient temperature (20°C)
[Edited on 9-12-2019 by Ubya]Dan Vizine - 17-12-2019 at 19:42
When you ampoule iodine under vacuum you can melt it to a liquid. The vacuum also promotes rapid crystal rearrangement and you can get some really
pretty crystals.
Even sublimed reagent grade iodine must be resublimed prior to sample preparation or brown impurities adhere to the glass.
I store both Br and I at room temperature in the glass bottles with special caps that the chemical industry sells them in. Very handy if you can get
them. No leakage problems over years.
[Edited on 12/18/2019 by Dan Vizine]Tsjerk - 18-12-2019 at 01:52
Very nice sample Dan! Although no one would have expected differently from you of course. Abromination - 18-12-2019 at 08:00
That is a beautiful sample.
Also, I have had little luck keeping iodine in media bottles, it still manages to escape. I would suggest trying one of those glass jars with the
pressure sealing glass lids. It still isn’t perfect but its pretty good. All of the bottles stored near my iodine have purple discolored labels from
the sealed bottle, even though it had secondary containment.
You also could try a bit of Al foil around the seal, thats how I stop HCl from leaking out of my acid bottle.Dan Vizine - 18-12-2019 at 10:04
Thanks, Tsjerk and Abromination.
In order for a cap to succeed with these materials, it has to do a few different things.
It needs to present an inert face to the material, and this is nearly always made of Teflon. But Teflon has no springiness, which, as Abromination
suggested, is desirable in a seal and so the Teflon has to be backed by a chemically-resistant rubber (like Viton). Finally, the cap itself needs to
be a robust one (like I think media bottles have?) that can squeeze the layers tightly onto the mouth of the bottle. The Teflon should be as thin as
possible so that the closing pressure can deform it. eBay can be a convenient source for some things that you may not have laying around.
eesakiwi - 5-2-2020 at 05:54
I did my iodine experiments over wax paper & stored it in a small wax lined jar.Fantasma4500 - 18-11-2020 at 09:34
hey i just wanted to share my findings from when i messed around with iodine some time ago, i always cover my experiments up with aluminium foil to
seal the deal
elemental iodine formed and it attacked the aluminium foil, forming aluminium iodide
i heat it up with a gas torch and rapidly i had thick iodine vapours coming off, i would shoot maybe 200*C this happens at, these fumes should be easy
to collect and im sure aluminium iodide is quite insoluble in water, should be easy to make by double displacement from potassium iodide.Bedlasky - 18-11-2020 at 09:49
AlI3 is quite soluble in water.Fantasma4500 - 21-11-2020 at 04:50
it appears to be soluble in water indeed, might have to carefully dry it out before trying to use it for making aluminium iodide then, it hydrolyses
in water to form HI, an excess of aluminium hydroxide would make sense then.
