The reaction occurs in which of the given galvanic cell? {1}{2}{H_2(g)} + {AgCl(s)} {H^+(aq)} + {Cl^-(aq)} + {Ag(s)}

Strategy: Break down the given net cell reaction into its oxidation (anode) and reduction (cathode) half-cells. Then, construct the cell notation following the "Anode | Solution | Cathode" convention.

Step 1: Identify half-reactions

• Anode (Oxidation): $\frac{1}{2}\ce{H2(g) \rightarrow H^+(aq) + e^-}$. This requires a Platinum (Pt) electrode and acidic medium.
• Cathode (Reduction): $\ce{AgCl(s) + e^- \rightarrow Ag(s) + Cl^-(aq)}$. This is a metal-insoluble salt electrode.

Step 2: Construct cell notation

1. Anode Side: $\ce{Pt|H2(g)|H^+(aq)}$
2. Cathode Side: $\ce{Cl^-(aq)|AgCl(s)|Ag}$
3. Electrolytic bridge: Both half-reactions can occur in an environment containing $\ce{H^+}$ and $\ce{Cl^-}$ (i.e., $\ce{HCl}$).

Conclusion: The notation is $\ce{Pt|H2(g)|HCl(sol^n)|AgCl(s)|Ag}$.

$\boxed{\text{Answer: (a) } \ce{Pt|H2(g)|HCl(sol^n)|AgCl(s)|Ag}}$