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Topic: Test of iodine in salt with lemon  (Read 8429 times)

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Offline jhernandezf

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Test of iodine in salt with lemon
« on: April 13, 2008, 03:58:16 PM »
I made a test to look for iodine in salt.  I used one recommended by UNICEF  : Salt becomes purple when lemon juice is mixed with it.  Perfect, but I do not know why this occurs. Why lemon does that on salt.

Any help on this will be greatly appreciated


Offline english

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Re: Test of iodine in salt with lemon
« Reply #1 on: April 13, 2008, 04:00:55 PM »
Isn't iodine solid purple?  Does this mean you're getting a deposition of iodine when you add lemon juice?  Possibly a redox reaction?

Offline Arkcon

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Re: Test of iodine in salt with lemon
« Reply #2 on: April 13, 2008, 04:54:03 PM »
Is there starch present, in your sample or your test reagent salt?  The iodine, is it free iodine (the brown or purplish-black crystals, with a lustrous almost metallic sheen) or is it a salt of iodine (can be white in color)?


It appears you were performing a test, something like this one:
but, some more specifics about your application are needed.
« Last Edit: April 16, 2008, 01:03:19 PM by Arkcon »
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

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