Convention in electrochemical cell notation While writing the cell notation for a cell, doesn't one have to write the two states in which a species exists in a sequence appropriate to the reaction in which they participate?
For example, in the Daniell cell reaction, shouldn't it always be written $\ce{Zn}|\ce{Zn^2+}$, and never, $\ce{Zn^2+}|\ce{Zn}$?
I didn't see anything in the definitions, and I saw a question asking for the cell reactions for this;
$$\ce{Pt,Cl2}|\ce{Cl^-(aq)}||\ce{Ag^+(aq)}|\ce{Ag}$$
Obviouly, chlorine doesn't react in that direction, but gets oxidised.
Good question. You can remember the cell notation with the mnemonic &quot;reduction on the right.&quot;
So, on the right hand side, you should reduction process and on the left hand side you should show the oxidation process.
For example, for a Daniel cell, one can write
$$\ce{Zn|Zn^{2+}, SO_4^{2−}}||\ce{SO_4^{2−},Cu^{2+}}|\ce{Cu}$$
Now coming to your cell, $$\ce{Pt,Cl_2}|\ce{Cl^-(aq)}||\ce{Ag^+(aq)}|\ce{Ag}$$ is indeed written incorrectly because the writer seems to have the misconception that even in the cell notation, half cells must be written as a reduction.