If `E_(1),E_(2)` and `E_(3)` are the emf values of the three galvanic cells respectivley
(i)`Zn|Zn^(2+)(1M)||Cu^(2+)(0.1M)|Cu`
(ii) `Zn|Zn^(2+)(1M)||Cu^(2+)(1M)|Cu`
(iii) `Zn|Zn^(2+)(0.1)||Cu^(2+)(1M)|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

`Zn+Cu^(2+)rarrZn^(2+)+Cu`
`E_("cell")=E_("cell")^(@)-(0.0591)/(2)"log"([Zn^(2+)])/([Cu^(2+)])`
Lesser the `[Zn^(2+)]//[Cu^(2+)]` value more will be `E_("cell")`
for (i) `([Zn^(2+)])/([Cu^(2+)])=(1)/(01)=10`
for (ii) `([Zn^(2+)])/([Cu^(2+)])=(1)/(1)=1` and
for (iii) `([Zn^(2+)])/([Cu^(2+)])=(01)/(1)=0.1`
Hence `E_(3)gtE_(2)gtE_(1)`