Galvanic cells generate electrical energy at the expense of a spontaneous redox reaction. In an electrode concentration cell two like electrodes having different concentrations, either because they are gas electrodes operating at different pressures or because they are amalgams (solutions in mercury) with different concentrations are dipped into the same solution.
Eg. An example is a cell composed of two chlorine electrodes with different pressure of `Cl_(2)`:
`Pt_(L)|Cl_(2)(P_(L))|HCl(aq)|Cl_(2)(P_(R))|Pt_(R)`
Where `P_(L)` and `P_(R)` are the `Cl_(2)` pressure at the left and right electrodes.
Calculate the EMF of the electrode concentration cell represented by :
`Hg-Zn(c_(1))|Zn^(+2)(aq)|Hg-Zn(c_(2))`
At `25^(@)C.c_(1)=2g` of `Zn` per `100g` of `Hg` and `c_(2)=1g` of `Zn` per `50g` of `Hg`

Options

A. `0.059V`
B. `3`
C. `0`
D. data insufficient

Answer

C

Explanation

`E_("cell")=E_("cell")^(@)-(RT)/(nF)InQ`
`E_("cell")=0-(RT)/(nF) In[(C_(2))/(C_(1))]`
`=-(RT)/(nF) In[(1/50)/(2/100)]`
`=0V`