I am currently doing a project on electrolysis, and I was wondering if the reduction potential (ie. $E^0$) will affect the rate of electrolysis. In other words, across different cells with differing $E^0$ values, is there a trend in the rate of electrolysis of these cells? Why or why not? I have seen other similar questions but all were talking about the ease of discharge/selective discharge of ions, which is not what I am looking for.


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    $\begingroup$ Standard Reduction Potentials represent the free-energy released or required to drive a specific half-reaction to completion. Depending on the species which react/are produced, this value will vary. Since free-energy doesn't hold a direct correlation with kinetics, then a relationship between Standard Reduction Potentials and reaction speed shouldn't be expected. In saying that, however, in the case of an electrolytic cell, increasing the external voltage will typically increase this rate of reaction. $\endgroup$ – XeLa Oct 31 '17 at 7:22
  • $\begingroup$ @XeLa so supposing I have a constant external voltage, but the voltage required to drive forward the reaction is lower than this external voltage, will the "surplus voltage" increase the rate of reaction? $\endgroup$ – Russell Ng Oct 31 '17 at 7:27
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    $\begingroup$ After factoring in any cell resistance/heat dissipation, then (in a sense) yes, it should. However, applying a voltage* greater than that necessary for your specific reaction can lead to additional unwanted half-reactions occurring at the electrodes. Just keep that in mind! *Let me just emphasise that its ultimately, however, the current which drives the reaction - voltage is just the result. $\endgroup$ – XeLa Oct 31 '17 at 7:33
  • $\begingroup$ @XeLa ah I see, thanks for the clarification! $\endgroup$ – Russell Ng Oct 31 '17 at 7:38

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