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woelen
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This FeI2/KOH method does not sound like a pleasant method to me. In practice it will be very hard to make reasonably pure KI with this, much harder
than with I2 + KOH. I also would use excess iron to be sure that all I2 reacts and then rinse all FeI2 from the excess of iron. I2 can be measured
reasonably accurately. KOH, on the other hand, is very bad when it comes to precise measurements. It usually contains some water and this may be
anything between a few percent up to 15%. If you want really good results then you first need to titrate the FeI2 solution and the KOH solution for
concentration and then add the right amounts of liquid to each other. Both excess FeI2 and excess KOH are not easily removed from KI, so you need to
work very precisely and you definitely need one or mayeb even two recrystallizations of KI.
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blogfast25
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I don't think there's a real need for titration here. I use KOH to precisely neutralise things all the time. Calculate the precise amount of KOH
needed, in the knowledge that it contains at least 10 % water. Add this, then bit by bit add more until pH 7 - 9. Not very hard.
If you start from KOH + I2, you basically have the same problem: you'll always be a bit off on the actual amount of KOH used and you'll need to
recrystallise your KI/KIO3 too.
I think the Fe/I2/KOH method is worth a shot, if only to satisfy curiosity.
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K12Chemistry
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Ok I have £2.20,
I need to save up to buy iodine, koh and iron (unless i find steel wool)
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AndersHoveland
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What if you added a copper salt? That would react with the iodide to precipitate out insoluble CuI and iodine in elemental form (which is not very
soluble in water so long as all the iodide is used up).
2 Cu+2 + 4 I- --> 2 CuI + I2
I'm not saying let's go kill all the stupid people...I'm just saying lets remove all the warning labels and let the problem sort itself out.
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woelen
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What do you want to reach with this? The goal is pure KI and I do not see how this relates to your suggestion of adding a copper salt.
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blogfast25
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Hoveland: do READ the thread before spouting irrelevant nonsense, it's about MAKING iodide, not destroying half one's stockpile of I2 as CuI.
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