Ask A Scientist© Chemistry Archive

name        Jason
status      student
age         15

Question -  how do i crystalize iodine out of the stuff you buy for wounds?
How pure would the crystals be?
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Jason-
    Tincture of Iodine is very dilute. Pure Iodine is toxic, and should not
be handled by anyone except a professional. Dilute solutions of iodine are
used to kill bacteria as in tincture of iodine. My water purification system
for when I go backpacking also has trace amounts of iodine to kill bacteria.
If you need iodine as a part of a science project, I suggest you ask your
teacher if you can use it under their careful supervision.

Bob Blaus
York High School
Elmhurst, IL
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he concentration of iodine in "tincture of iodine" that you find in the
pharmacy is very small. I think less than 1 percent, but it will say so on
the bottle. In principle, one could evaporate of the water/alcohol in the
"tincture" but the amount of iodine you recover will be very small. Also
iodine itself is fairly volatile so even evaporation is not going to give a
significant yield of iodine.

Vince Calder
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