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Topic: Redox: Where does the oxidation state value of 5 come from in this working?  (Read 2569 times)

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Offline Generic Username

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I've copied this (attached) from another forum, but I can't see where the difference in oxidation numbers (given as 5 for Fe) comes from. 4 for I (having gone from +5 to +1) I  can understand, but not Fe.
« Last Edit: February 19, 2016, 05:38:22 AM by Generic Username »

Offline mjc123

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It's impossible to say, as none of the equations are balanced.

Offline Generic Username

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It's impossible to say, as none of the equations are balanced.

Thanks mjc123,
If it's any help, here is the complete working which I've translated:

Offline mjc123

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OK, that makes things clearer. So 5 I(+5)  :rarrow: I(+1), a change of -4
8 I(-1)  :rarrow: I(+1), a change of +2
4 Fe(+2)  :rarrow: Fe(+3), a change of +1
Total change = 5*-4 + 8*2 +4*1 = 0. Hurrah!
The change of 5 for Fe I can only imagine someone misread 2+ as 2-.

Offline Generic Username

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OK, that makes things clearer. So 5 I(+5)  :rarrow: I(+1), a change of -4
8 I(-1)  :rarrow: I(+1), a change of +2
4 Fe(+2)  :rarrow: Fe(+3), a change of +1
Total change = 5*-4 + 8*2 +4*1 = 0. Hurrah!
The change of 5 for Fe I can only imagine someone misread 2+ as 2-.

Hi mjc123,
Thanks very much for your help. I also wondered about the Fe being misread, but everywhere I checked verified it as being +2.

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