The half-cell electrode potential for the metal reduction of zinc and iron are -
ID: 484775 • Letter: T
Question
The half-cell electrode potential for the metal reduction of zinc and iron are - 0.76 and - 0.44 V_SHE, respectively (See EMF Table). The corrosion rate of zinc would be expected to be much higher than that of iron. However, the corrosion rate of zinc in acidic solution is somewhat lower than that of iron. Explain why this is the case. Use the Evan's diagram to illustrate your answer. Please carefully plot the diagram and ensure labeling the axis and indicate the units. Please ensure showing the important parameters are shown in the graph with their values.Explanation / Answer
Zinc is not used in contact with acid and strong alkaline solutions, because it corrodes rapidly in such media.
Very dilute concentration of acids accelerate corrosion rates beyond the limit of usefulness. Alkaline solutions of moderate strength are much less corrosive than corresponding concentrations of acid, but are still corrosive enough to impair the usefulness of zinc.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.