# 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.

$$\ce{Zn|Zn^{2+}, SO_4^{2−}}||\ce{SO_4^{2−},Cu^{2+}}|\ce{Cu}$$
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.