Homework Problem 14.55b  [ENDORSED]

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Lily Guo 1D
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Homework Problem 14.55b

Postby Lily Guo 1D » Tue Feb 20, 2018 11:30 pm

"A 1.0 m NiSO4(aq) solution was electrolyzed by using inert electrodes. Write (a) the cathode reaction; (b) the anode reaction. (c) With no overpotential or passivity at the electrodes, what is the minimum potential that must be supplied to the cell for the onset of electrolysis?"

The solutions manual has the anode reaction as 2H2O (l) --> O2 (g) + 4H+ (aq) + 4e-, which has an E°= +1.23V, but why is the anode reaction not the oxidation of the SO4 2- ion if that reaction has a lower E° = +0.17V? The book says to choose the oxidation reaction with the least positive/most negative standard reduction potential (E° value), so I'm a little confused.

Eli Aminpour 2K
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Re: Homework Problem 14.55b

Postby Eli Aminpour 2K » Tue Feb 20, 2018 11:35 pm

In electrolysis, an electric current is passed through the substance. It is different than the chemical reaction that occurs in an galvanic cell. That is why you focus on the most positive standard reduction potentials

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Re: Homework Problem 14.55b  [ENDORSED]

Postby Chem_Mod » Fri Mar 16, 2018 10:31 am

Return to “Work, Gibbs Free Energy, Cell (Redox) Potentials”

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