A button cell used in watches functions as following:
Zn(s) + Ag₂O(s) + H₂O(l) ⇌ 2Ag(s) + Zn²+(aq)+2OH⁻(aq)
If half cell potentials are:
Zn² + (aq)+2e −→ Zn(s);E° = −0.76V
Ag₂O(s) + H₂O(l) + 2e −→ 2Ag(s) + 2OH^−(aq),E° = 0.34V
The cell potential will be:
A. 1.10 V
B. 0.42 V
C. 0.84 V
D. 1.34 V