The standard oxidation potentials of Zn, Cu, Ag and Ni electrodes are +0.76,-0.34,-0.80 and +0.25 V respectively . Which of the following reaction will provide maximum voltage ?

Options

A. `Cu+2Ag^(+)(aq)toCu^(2+)(aq)+2Ag`
B. `Zn+2AG^(+)(aq)toZn^(2+)(aq)+2Ag`
C. `H_(2)+Ni^(2+)(aq)to2H^(+)(aq)+Ni`
D. `Zn+Cu^(2+)(aq)toZn^(2+)(aq)+Cu`

Answer

B

Explanation

For (a) `E^(@)=-0.34+0
.80=0.46V`
(b) `E^(@)=0.76+0.80=1.56V`
(c ) `E^(@)=-0.25V`
(d) `E^(@)=0.76+.34=1.00V`
(e ) `E^(@)=0.76V`
`therefore` Correct answer (B) .