`E_(1),E_(2)` and `E_(3)` are the emf values of the three galvanic cells respectively.
(i) `Zn|Zn_(1M)^(2+)||Cu_(0.1M)^(2+)|Cu`
(ii) `Zn|Zn_(1M)^(2+)||Cu_(1M)^(2+)|Cu`
(iii) `Zn|Zn_(0.1M)^(2+)||Cu_(1M)^(2+)|Cu`
Which one of the following is true ?

Options

A. `E_(2)gtE_(3)gtE_(1)`
B. `E_(3)gtE_(2)gtE_(1)`
C. `E_(1)gtE_(2)gtE_(3)`
D. `E_(1)gtE_(3)gtE_(2)`

Answer

B

Explanation

Emf of the cell `=E_("cell")^(@)-(0.0591)/(n)log_(10)[(Zn^(2+))/(Cu^(2+))]`
Higher the `([Zn^(2+)])/([Cu^(2+)])` ratio lower is the emf of cell.
(i) `"log"([Zn^(2+)])/([Cu^(2+)])=10,` (ii) `"log"([Zn^(2+)])/([Cu^(2+)])=1`
(iii) `"log"([Zn^(2+)])/([Cu^(2+)])=0.1`
So, order is `E_(3)gtE_(2)gtE_(1)`.