thunderfvck
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Coldfinger improvisations
Well! I prepared some iodine today, twas very exciting. Very messy. My counter top is covered with stains now as a result. Oh well!
Anyway. I need to purify it, and the best way to do, of course, is to sublime the iodine!
I tried it already with very poor results. I had a watch glass over a 250 ml beaker (which contained the crude iodine). Over the watch glass was a bag
filled with water/ice. THis got very messy, two of the bags burst and, yeah...Anyways, I got little iodine on top. Shifting the watch glasses also
proved to be a bad idea as much I2 vapour escaped...To make matters worse, my iodine was very wet, and so the resublimed iodine also carried quite
some moisture. Anyways, I aborted that mission and stuffed it into the freezer.
I believe I'll try using my condenser to sublime it this time, I've read that this works quite well. I just need some tubing! I'm also
drying my iodine now over CaCl2, so hopefully I won't run into another sticky mess (I've read that the sublimed iodine, when dry, is VERY
brittle and easy to collect, we'll see).
I'm just wondering what any of your ideas are about this. What do you use when you need to sublime something?
Oh, and one more thing kind of off topic...I converted the I2 in the tincture to NaI by adding NaOH. I don't know what the formula is and
it's kind of bugging me...
I2 + 2NaOH --> NaI + NaOI + H2O
??
[Edited on 4-5-2004 by thunderfvck]
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Geomancer
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Sounds familiar. CaCl<sub>2</sub> works, but may release water if you heat too strongly. One of my early attempts had water contamination,
possibly from this source but more likely water seeping under the lid. I used a glass jar with a layer of LDPE film trapped under the lid to prevent
it from corroding too much. The lid was cooled directly with ice and the apparatus was heated in boiling salt (or CaCl<sub>2</sub>, I
can't remember) water. Lots of water around. Later, I just left the jar on the radiator. That produced dry crystals but took a while.
As for the mess, make yourself a slurry of vitamin C tablets. I discovered that even tiny iodine dust particles, when they land on clothing, will
each produce a nice brown spot. But the ascorbic acid will reduce them, and remove the stain entirely even after many minutes (haven't tried
longer periods). Works on skin, too, and is a nice way of decontaminating your apparatus.
I'm not familiar with your NaOH reaction. Disproportionation of hypoiodite, perhaps?
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chemoleo
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How about dissolving the crude I2 product in absolute ethanol? I2 will go in solution, while any remaining salts won't.
Then add a large excess of ice cold water, and filter off the wet I2 precipitate (probably paper filters are not good, so maybe just let it settle).
Then simply put the I2 into a well-airated place, and let the water evaporate.
Don't let it take too long, as the I2 will sublime too, of course.
I remember once leaving a big I2 crystal (twice the size of a pea) in the open for a week, and it lost half of its weight.
Prolonged storage of dried I2 in a bottle will produce beautiful metallic like crystals everywhere in the bottle - which unfortunately dont last once
in the outside.
PS I should add that you will have a fair amount of loss with this procedure... if you get 80% of the original I'd be happy.
[Edited on 4-5-2004 by chemoleo]
Never Stop to Begin, and Never Begin to Stop...
Tolerance is good. But not with the intolerant! (Wilhelm Busch)
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thunderfvck
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I had read an interesting method by Shorty from the-hive in which he used a cleared out halogen light bulb (those big mothers). He basically had that
do the collecting of the iodine and had a plunger or somethign to push them all out. That sounds quite good to me.
About the ethanol, if you add it to dissolve the iodine and then crash it out again with water, won't the crap just go back into the water again,
possibly contaminating my product once more? It could be repeated, yes, but I imagine I'll lose quite a bit of it - something I cannot stand for!
Besides, subliming it is just so cool. And the crystals are absolutely beautiful.
I'll post the link to Shorty's procedure if anyone is interested.
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