H half rxns

[aisteles1G]

i'm really confused on how to write out half rxns from a cell diagram that use H2 I HCL, in the book chapter there is an example and it writes it out as 1/2 H2--> H+ + e- but HCL isn't even incorporated into the half rxn? Do you always leave out the anion when dealing with hydrogen in an oxidation half reaction? Any help would be greatly appreciated, thanks!

[MaanasO 1A]

In this case, HCL completely dissolves into H+ and Cl-, so you can ignore the Cl- for the time being. That's why they only use H+.