For the reaction  Pt /H2(1atm) / H+(aq) // Cl–(aq) /AgCl/Ag  Kc (equilibrium constant) is represented as

From the given cell notation the cell reaction is Anode : 12H2(1atm)⇌H(aq)++e- Cathode: AgCl(s)+e-⇌Ag(s)+Cl(aq)-AgCl(s)+12H2(1atm)⇌H(aq)++Cl(aq)-+Ag(s) KC=H+Cl-For  all Solids and pure liquids, active mass = 1