Question

The standard reduction potentials for $Z{n}^{2+}|Zn,N{i}^{2+}|Ni$ and $F{e}^{2+}|Fe$ are $-0.76,-0.23$ and $-0.44$ respectively. The reaction $X+Y^{2+}$ $\to$ $X^{2+}+Y$ will be spontaneous when:

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

Answer 1

The correct option is D X = Zn, Y = Ni

For a reaction to be spontaneous, $\Delta G^{\circ }$ should be negative and for that $E_{cell}^{\circ }$ should be positive.