The standard reduction potentials 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+)to 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

Explanation

To determine when the reaction \( X + Y^{2+} \rightarrow X^{2+} + Y \) will be spontaneous, we need to analyze the standard reduction potentials of the half-reactions involved. The reaction will be spontaneous when the cell potential \( E^\circ_{\text{cell}} \) is greater than 0.

### Step-by-Step Solution:

1. **Identify the Half-Reactions**:
- We have three half-reactions with their standard reduction potentials:
- \( \text{Zn}^{2+} + 2e^- \rightarrow \text{Zn} \) (E° = -0.76 V)
- \( \text{Ni}^{2+} + 2e^- \rightarrow \text{Ni} \) (E° = -0.23 V)
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