NEETChemistryElectrochemistryMCQ+4 / −1
A button cell used in watches function as following.
Zn(s) + Ag2O(s) + H2O(l) 2Ag(s) + Zn2+(aq) + 2OH(aq)
If half cell potentials are
Zn2+(aq) + 2e Zn(s); Eo = 0.76 V
Ag2O(s) + H2O(l) + 2e 2Ag(s) + 2OH(aq), Eo = 0.34 V
The cell potential will be
Zn(s) + Ag2O(s) + H2O(l) 2Ag(s) + Zn2+(aq) + 2OH(aq)
If half cell potentials are
Zn2+(aq) + 2e Zn(s); Eo = 0.76 V
Ag2O(s) + H2O(l) + 2e 2Ag(s) + 2OH(aq), Eo = 0.34 V
The cell potential will be
- A0.84 V
- B1.34 V
- C1.10 V
- D0.42 V
View written solutionFree
Correct answer: C
At anode :Zn2+(aq) + 2e Zn(s); Eo = 0.76 V
At cathode : Ag2O(s) + H2O(l) + 2e 2Ag(s) + 2OH(aq), Eo = 0.34 V
E°cell = E°cathode – E°anode
= 0.34 – (–0.76) = 1.10 V
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