Question

Zinc is used to protect iron from rusting because

• A. $E_{\text {red }}^{\circ}$ of $Zn >E_{\text {red }}^{\circ}$ of $Fe$
• B. $E_{\text {ox }}^{\circ}$ of $Z n>E_{\text {ox }}^{\circ}$ of $Fe$
• C. zinc does not melt easily
• D. zinc is cheap.

Answer 1

Answer: (A)

Zinc is used to protect iron from corrosion because it is more active metal than iron and it has more tendency to lose electrons with respect to iron. In other words, zinc has a negative reduction potential higher than that of iron.
$E _{ zn ^{2+}| Zn }^{\circ}=-0.76\, V$
$E _{ F e ^{2+}| Fe }^{ o }=-0.44\, V$