Cell diagram help.

[Brian Kwak 1D]

I had a question about the cell diagram. If the anode or cathode has elements that do not go under a phase change we annotate it as Fe3+(aq),Fe2+(Aq)ΙPt(s) right? Also when there is no phase change and no metal we add a inert metal to the cell diagram right??

[katherinemurk 2B]

You add an inert metal when the ions of the same element are in the same solution or when you have a gas and ion in the same solution

[Cody Do 2F]

When an anode or cathode do not undergo a phase change, you're correct that you use a comma to separate the two instead of a bar. It is important to note that if there is a situation like this, you should place the oxidized element first and then the reduced element. Using your example, Fe³⁺_(aq) is placed first since it's "more oxidized" (more positive, less negative) than Fe²⁺_(aq), which is "more reduced" (less positive, more negative).