Anode is always the site of oxidation thus anode half cell is Zn2+(aq)+2e−⟶Zn(s);E∘=−0.76 V Cathode half cell is Ag2O(s)+H2O(l)+2e−⟶2Ag(s)+2OHE−(aq);E∘=0.34 V=Ecathode ∘−Eanode ∘=0.34−(−0.76)=+1.10 V
A button cell used in watches functions as following \mathrm{Zn}(s)+\mathrm{Ag}_2 \mathrm{O}(s) & +\mathrm{H}_2 \mathrm{O}(l) \rightleftharpoons 2 \mathrm{Ag}(s) + \mathrm{Zn}^{2+}(\alpha q)+2 \mathrm{OH}^{-}(\alpha q) If half cell potentials are Zn2+(aq)+2e−Ag2O(s)+H2O(l)→Zn(s);E∘=−0.76 V+2e−→2Ag(s)+2OH−(aq),E∘=0.34 V The cell potential will be
Held on 30 Apr 2013 · Verified 9 Jul 2026.
1.10 V
0.42 V
0.84 V
1.34 V
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