Question

Standard electrode potentials are $Fe^{2+}/Fe \left(E^{\circ} = - 0.44\right)$
$Fe^{3+}/Fe^{2+} \left(E^{\circ} = 0.77\right)$
$Fe^{2+}, Fe^{3+}$ and $Fe$ blocks are kept together, then

• A. $Fe^{3+}$ increases
• B. $Fe^{2+}$ increases
• C. $Fe^{2+}/Fe^{3+}$ remains unchanged
• D. $Fe^{2+}$ decreases

Answer 1

Answer: (B)

Positive reduction potential for $Fe^{3+}/ Fe^{2+}$ couple suggest that $Fe^{3+}$ would reduce to $Fe^{2+}$ whereas negative reduction potential of $Fe^{2+}/Fe$ couple suggest that Fe would oxidise to $Fe^{2+}$.Therefore $Fe^{3+}$ and $Fe$ decrease whereas $Fe^{2+}$ increases.