Question

The standard reduction potentials at 298 K for single electrodes are given below.

Electrode	electrode potential (volt)
$\text{Mg}^{\text{2+}} \text{/Mg}$	$- \text{2} \text{.34}$
$\text{Zn}^{\text{2+}} \text{/Zn}$	$- \text{0} \text{.76}$
$\text{Fe}^{\text{2+}} \text{/Fe}$	$- \text{0} \text{.44}$

From this we can tell that

• A. Zn can reduce both $Mg^{2 +}$ and $Fe^{2 +}$
• B. Fe can reduce both $Mg^{2 +}$ and $Zn^{2 +}$
• C. Mg can reduce both $Zn^{2 +}$ and $Fe^{2 +}$
• D. Mg can reduce $Zn^{2 +}$ but not $Fe^{2 +}$

Answer 1

Answer: (C)

Metals with lower SRP can displace the metal with higher SRP from their solutions. Mg with lower $SRP (-2.34)$ can reduce both $Zn^{2 +} (-0.76) $ and $Fe^{2 +} (-0.44)$.