The standard reduction potential for `Zn^(2+)//Zn, Ni^(2+)//Ni` and `Fe^(2+)//Fe` are `-0.76, -0.23` and `-0.44V` respectively. The reaction `X + Y^(2) rarr X^(2+) + Y` will be spontaneous when:

Options

A. X = Ni, Y = Fe
B. X = Ni, Y = Zn
C. X = Fe, Y = Zn
D. X = Zn, Y = Ni

Answer

D

Explanation

`Zn+Fe^(2+)rarrZn^(+2)+Fe`
`Fe+NirarrFe^(2+)+Ni`
`Zn+Ni^(2+)rarrZn^(+2)+Ni`
All these are spontaneous