Consider the following concentration cell`:`
`Zn(s)|Zn^(2+)(0.024M)||Zn^(2+)(0.480M)|Zn(s)`
which of the following statements is `//` are correct?

Options

A. The `EMF` of the cell at `25^(@)C` is nearly `+0.039V.`
B. The `EMF` of the cell at `25^(@)C` is nearly `-0.039V`.
C. If water is added in `LHE`, so that the `[Zn^(2+)]` is reduced to `0.012 M`, the cell voltage increases.
D. If water is added in `LH` , so that the `[Zn^(2+)]` is reduced to `0.012M` , the cell voltage decreases.

Answer

a,c

Explanation

Cell reaction `:Zn^(2+)(0.484M) rarr Zn^(2+)(0.024M)`
`E_(cell)=0-(0.059)/(2) log ((0.024)/(0.480))=0.039V`
For `:Zn^(2+)(0.484M)rarr Zn^(2+)(0.12M)`
`implies E_(cell)=0-(0.059)/(2) log ((0.012)/(0.48))`
`=0.03(1.6)=0.048V`