permenganate

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Juan
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permenganate

Post by Juan »

I am having a problem with this
I have added L vit C (C6H8O6) 1mg/ml to a solution of permnganate KMO4 (0.005M) (at 4°C)
The mermenganate turned from purple to trensparent
I can't seem to find to right equilibre and how do i explain this result ( I did not add any acid slution, the ascorbic acid is acid thought!)

KMnO4 + C6H8O6 = K+ + C6H6O6 + Mn2+ + H2O?
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ChenBeier
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Post by ChenBeier »

The explanation is : Permanganate is an oxidiser and Ascorbic acid a reducer. Colour turns from purple to colourless

Permanganate : MnO4- + 8 H+ + 5 e- => Mn2+ + 4 H2O

Ascorbic acid: C6H8O6 + 6 H2O => 6 CO2 + 20 H+ + 20 e-

Sum:

4 MnO4- + 12 H+ + C6H8O6 => 4 Mn2+ + 6 CO2 + 10 H2O

H+ is donated from additional Acorbic acid.
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