Editing Nernst equation (section)

==Limitations==
In dilute solutions, the Nernst equation can be expressed directly in the terms of concentrations (since activity coefficients are close to unity). But at higher concentrations, the true activities of the ions must be used. This complicates the use of the Nernst equation, since estimation of non-ideal activities of ions generally requires experimental measurements. The Nernst equation also only applies when there is no net current flow through the electrode. The activity of ions at the electrode surface changes [[electrochemical kinetics|when there is current flow]], and there are additional [[overpotential]] and resistive loss terms which contribute to the measured potential. 

At very low concentrations of the potential-determining ions, the potential predicted by Nernst equation approaches toward {{math|±∞}}. This is physically meaningless because, under such conditions, the [[exchange current density]] becomes very low, and there may be no thermodynamic equilibrium necessary for Nernst equation to hold. The electrode is called unpoised in such case. Other effects tend to take control of the electrochemical behavior of the system, like the involvement of the [[solvated electron]] in electricity transfer and electrode equilibria, as analyzed by [[Alexander Frumkin]] and B. Damaskin,<ref>[[J. Electroanal. Chem.]], 79 (1977), 259-266</ref> Sergio Trasatti, etc.

===Time dependence of the potential===
The expression of time dependence has been established by Karaoglanoff.<ref>{{citation |first=Z. |last=Karaoglanoff |author-link=Zakhari Karaoglanoff |title=Über Oxydations- und Reduktionsvorgänge bei der Elektrolyse von Eisensaltzlösungen |language=de |trans-title=On Oxidation and Reduction Processes in the Electrolysis of Iron Salt Solutions |journal=Zeitschrift für Elektrochemie |volume=12 |issue=1 |pages=5–16 |date=January 1906 |doi=10.1002/bbpc.19060120105 |url=https://zenodo.org/record/1424952 }}</ref><ref>{{citation |title=Electrochemical Dictionary |editor1-first=Allen J. |editor1-last=Bard |editor2-first=György |editor2-last=Inzelt |editor3-first=Fritz |editor3-last=Scholz |contribution=Karaoglanoff equation |pages=527&ndash;528 |url=https://books.google.com/books?id=4TBWg3dIyKQC&pg=PA527 |publisher=Springer|isbn=9783642295515 |date=2012-10-02 }}</ref><ref>{{citation |title=Introduction to Polarography and Allied Techniques |first=Kamala |last=Zutshi |pages=127–128 |url=https://books.google.com/books?id=WmiaCVH-MEIC&pg=PA127 |isbn= 9788122417913|year=2008|publisher=New Age International }}</ref><ref>{{Cite book |url=https://books.google.com/books?id=zCMSAAAAIAAJ&pg=PA316 |title=The Journal of Physical Chemistry |date=1906 |publisher=Cornell University |language=en}}</ref>