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Topic: I2 + 2KOH ---> KOI + KI + H2O???  (Read 5856 times)

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Offline Jango

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I2 + 2KOH ---> KOI + KI + H2O???
« on: December 01, 2010, 12:08:23 PM »
I've been electrolysing potassium iodide solution. Iodine formed at the anode, while hydrogen formed at the cathode. The iodine went into solution straight away; turning the solution into an orange colour.

Would the iodine in solutuion react with the potassium hydroxide that is also in solution to form potassium hypoiodite? Or is iodine not reactive enough?

Also, the solution is in my garage (it's winter, so the temperature in there is barely above 32'F).

Offline Schrödinger

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Re: I2 + 2KOH ---> KOI + KI + H2O???
« Reply #1 on: December 01, 2010, 03:24:08 PM »
Iodine gets reabsorbed in the solution because of the following reaction :



turns the solution orange.

About the reaction with KOH, I think it is possible (of course, there will be competition between that reaction and the one above that produces KI3), although I vaguely remember reading somewhere that a hot concentrated solution can result in the formation of . In that case, everything else in the reaction remains the same, just replace KOI with KIO3

I think you're idea of a disproportionation reaction is correct
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Offline Jango

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Re: I2 + 2KOH ---> KOI + KI + H2O???
« Reply #2 on: December 02, 2010, 12:23:46 PM »
I've had the electricity on for a total of about 20 minutes, and the solution has now become a dark, purple colour. Is this a buildup of elemental iodine?

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