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Topic: Chemistry Investigation- Starch/Iodine Complex  (Read 4087 times)

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Cat2020

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Chemistry Investigation- Starch/Iodine Complex
« on: March 31, 2006, 11:54:23 AM »
I am currently in the middle of my advanced higher chemistry investigation, but i have run into some problems. I am investigating the starch-iodine complex, and currently I can find very little literature on this topic. To try and investigate the properties of this complex i have tried several methods: Heating the blue black complex results in the decolourisation of the solution, and i have assumed this is due to the denaturing of the starch amylose helix releasing the Iodide ions. However, i have no evidence to back this theory up. I have also tried electrolysing the solution containing the complex, as i thought this may lead to the decolorisation due to destrucion of the iodide ions, however , it did not and i do not know why this was so. I have also added ethanol and toluene to the solution, resulting in decolorisation. I guessed this may due to the OH bonds interfering with the complexes H bonds but andy suggestions would be welcome!  Finally i added excess reducing agent ( silver nitrate) to remove the iodide ions, resulting in decolorisation..
If anyone has any knowledge about this topic, or can suggest any possible explanations to my results or possibly any other experiments i should do it would be very much appreciated!
Also, if you know of any literature on the subject that would be helpful too  (-:
Thank you!
« Last Edit: April 01, 2006, 07:52:12 AM by Cat2020 »

Offline Yggdrasil

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Re:Chemistry Investigation- Starch/Iodine Complex
« Reply #1 on: April 01, 2006, 11:30:48 PM »
http://en.wikipedia.org/wiki/Starch#Tests

Unfortunately, I don't know of any more definitive sources which comment on this subject.

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