The oxidation ptentials of `Zn, Cu, Ag, H_2` and Ni are `0.76, - 34, - 0.80 . 0. 00, 0. 25` volt, respectively. Which of the following reactions will provide maximum voltage ?

Options

A. `Zn +Cu^(2+) rarr Cu +Zn^(2+)`
B. `Zn +2Ag^(+) rarr 2Ag +Zn^(2+)`
C. `H_(2) +Cu^(2+) rarr 2H^(+) +Cu`
D. `H_(2) +Ni^(2+) rarr 2H^(+) +Ni`

Answer

B

Explanation

`E_("cell")^(@)=E_(c )^(@)-E_(p)^(@)` check for each reaction.