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Topic: transition metals  (Read 2787 times)

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Offline jjc

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transition metals
« on: July 01, 2008, 11:12:20 PM »
hi I would like to ask why is there a difference between the following redox potentials?

[Fe(H2O)6]3+ + e-  <---> [Fe(H2O)6]2+
and
[Fe(CN)6]3- + e-  <---> [Fe(CN)6]4-

Thanks much

Offline macman104

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Re: transition metals
« Reply #1 on: July 01, 2008, 11:18:42 PM »

Offline vhpk

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Re: transition metals
« Reply #2 on: July 02, 2008, 12:13:41 AM »
hi I would like to ask why is there a difference between the following redox potentials?

[Fe(H2O)6]3+ + e-  <---> [Fe(H2O)6]2+
and
[Fe(CN)6]3- + e-  <---> [Fe(CN)6]4-

Thanks much
CN- is a strong ligand and it stabilises Fe(III) w.r.t Fe(II) -> it makes [Fe(CN)6]3- more difficult to be reduced to Fe(II) compared to [Fe(H2O)6]3+. Hence, the E0 value of [Fe(CN)6]3- is lower
Genius is a long patience

Offline jjc

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Re: transition metals
« Reply #3 on: July 02, 2008, 02:44:00 AM »
thanks vhpk!

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