I've stumbled across a problem that I need help on, it is mostly Electrochemistry and I will show my work.

  1. Line Notation Error: $$\ce{Fe~|~Fe^{+2}~||~Cl^{-},Cl2~|~Pt}$$

After that, I understood that Iron is at the anode and is being oxidized, however I do not know what was going on with Chlorine, it looks like it is being oxidized while it is supposed to be reduced.

Ok all right then, maybe this is a non-spontaneous reaction. Can this be possible, can chlorine be used as an oxidation reaction? And if so how can we calculate the Voltage?

Figured out that my professor was wrong. :) Will delete.


Ok first of all I didn't know what a comma was supposed to mean, but I assumed it was a typo.

No, it means that $\ce{Cl2}$ and $\ce{Cl-}$ are in the same phase. Chlorine gas is dissolved in a solution containing chloride.

It is the first double bar that puzzles me. Shouldn't that be a single one?


The normative reference for the notation of galvanic cells is found in the Compendium on Analytical Nomenclature. An online version of this compendium, which is also known as The Orange Book, can be found at the IUPAC.

In chapter 1 of this work, a subsection titled Conventions concerning the signs of electric potential differences, electromotive forces, and electrode potential explicitely states:

A single vertical bar ( | ) should be used to represent a phase boundary, a dashed vertical bar (¦) to represent a junction between miscible liquids, and double dashed vertical bars (¦¦) to represent a liquid junction in which the liquid junction potential is assumed to be eliminated.

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  • $\begingroup$ Yes it should be a single one. But how can it also be reduced? $\endgroup$ – Asker123 Apr 22 '15 at 21:17
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    $\begingroup$ "a comma separates two components in the same phase" - Allen J. Bard -Electrochemical methods. Fundamentals and applications $\endgroup$ – Jaroslav Kotowski Apr 23 '15 at 12:40
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    $\begingroup$ You mean the double bar? Isn't that supposed to be the salt/ion bridge. I have seen galvanic cells written this way many times, like they introduce this in the german Wikipedia. Does it make a difference if there is one or two bars? $\endgroup$ – Martin - マーチン Apr 24 '15 at 4:19
  • $\begingroup$ @Martin Yes, it does. The single bar means phase boundary. $\endgroup$ – Klaus-Dieter Warzecha Apr 24 '15 at 4:26

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