For the cell Zn((s)) `|ZN^(2+) ((aq)) || M^(X+)((aq))|M((s))`, different half cells and their standard electrode potentials are given below :

` If E_(ZN^(2+)|ZN^(@))= -0.76V`, which cathode will give a maximum value of `E_(cell)^(@)` per electron transferred ?

Options

A. `Au^(3+)|Au`
B. `Fe^(3+)|Fe^(2+)`
C. `Fe^(2+)|Fe`
D. `Ag^(+)Ag`

Explanation

`E_(cell)^(0)` is an intensive property
`E_(cell)^(0)=E_(cathode)^(0)-E_(anode)^(0)`
Since `E_(Au^(3+)//Au)^(0)` has amximum standard Reduction potential `E_(cell)^(0)` will be maximum
`zn(s)|zn^(2+)||Au^(3+)|Au(s)`
`E_(cell)^(0)=0.20 implies (E_c^(0)-E_A^(0))_r=0.2 implies ( Q E_A^(0))`