A button cell used in watches functions as following
`Zn(s) + Ag _2 O(s) + H_2 O(l)`
`2 A g(s) + Zn^(2+) (aq) = 2 OH^- (aq)`
If half cell potentials are
`Zn^(2+) (aq) +2e^- rarr Zn (s) , E^@ =- 0. 76 V`
`Af_2 O(s) +H_2 O (l) +2e^- rarr`
`2Ag(s) + 2OH^- (aq) , E^@ =0. 34 V`.
The cell potential will be .

Options

A. `0.84 V `
B. `1.34 V`
C. `1.10 V `
D. `0.42 V`

Answer

C

Explanation

`E_(cell)^(@) = E_("cathode")^(@) - E_("anode")^(@)`
`=0.34 - (-0.76) = 1.10` V