Is this galvanic cell representation right?

### Question



> 
> **13.** In the galvanic cell:
> 
> 
> $$\ce{Pt(s) | I2(g) | I-(aq) || Fe^3+(aq) | Fe^2+(aq) | Pt(s)}$$
> 
> 
> 1. Representation of anode is incorrect and cell will not work.
> 2. $[\ce{Fe^3+}] = [\ce{Fe^2+}] = [\ce{I-}] = \pu{1 M}$ is sufficient for $E\_\mathrm{cell} = E\_\mathrm{cell}^\circ.$
> 3. $\ce{I-}$ gets oxidized to $\ce{I2}$ and $\ce{Fe^3+}$ gets reduced to $\ce{Fe^2+}.$
> 4. None of these.
> 
> 
> 


### Given Answer



> 
>  3. $\ce{I-}$ gets oxidized to $\ce{I2}$ and $\ce{Fe^3+}$ gets reduced to $\ce{Fe^2+}.$
> 
> 
> 


### My Thoughts


The representation of anodic half confuses me. I am unsure whether it is right representation. According to me, it should be $\ce{I-} | \ce{I2}$ (anodic half). It seems to me that answer should be 1.




The chapter 1 of the reference 1 describes the *Line Notation for Galvanic Cells* as follows:



> 
> A shorthand way of completely describing an electrochemical cell such as Galvanic cell is called line notation. It is a shorthand way of expressing the redox reaction progressing in the electrochemical cell. In this notation:
> 
> 
> 1. A slash (/) or a vertical line (|) represents a phase boundary, and a comma separates two components in the same phase. A double slash (//) or a double vertical line (||) represents a phase boundary whose potential is regarded as a negligible component of the overall cell potential (*e.g.*, salt bridge).
> 2. When a gaseous phase is involved, it is written adjacent to its corresponding conducting element.
> 3. The constituents of the cathode on the right and the constituents of the anode on the left.
> 4. The phases of all reactive species are listed and their concentrations or pressures are given if those species are not in their standard states (*i.e.* $\pu{1 bar}$ for gasses and $\pu{1M}$ for solutions).
> 
> 
> 


Thus, in the given cathode representation, both $\ce{Fe^3+ (aq)}$ and $\ce{Fe^2+ (aq)}$ are separated by a vertical line (|), which is an incorrect representation, according to the description (1) above. They should be actually separated by a comma (as $\ce{Fe^3+ (aq)}$, $\ce{Fe^2+ (aq)}$) because there is no phase separation between them (both are in same phase).


Also, according to the description (2) above, $\ce{I2 (g)}$ cannot be introduced into $\ce{Pt (s)}$ anode (as indicated in the representation) because $\ce{I2 (g)}$ is the product of the reaction, not a reactant. 


Based on these, given answers (1) and (3) should be correct. Also, OP's representation of 'anode half' is also correct since there is phase separation.


**References:**


1. Allen J. Bard, Larry R. Faulkner, In *Electrochemical Methods: Fundamentals and Applications*; Second Edition, John Wiley & Sons, Inc.: New York, NY, 2001 (ISBN 0-471-04372-9).


 1