Question

Metals having maximum to minimum resistance to corrosion
(A) Zinc
(B) Aluminum
(C) Copper
(D) Tin
(E) Gold
Choose the correct answer from the options given below:

• A. (E), (D), (C), (B), (A)
• B. (E), (B), (C), (D), (A)
• C. (A), (B), (C), (D), (E)
• D. (A), (C), (D), (E), (B)

Hint:

Noble metals like gold and platinum are most resistant to corrosion. Metals that form a strong passive oxide layer (like aluminum and titanium) are next. Metals used for sacrificial coatings (like zinc) are the least resistant.

Answer 1

The Correct Option is B

Step 1: Rank the metals by corrosion resistance in a standard environment, from greatest to least.

(E) Gold: Highly inert, offering exceptional resistance to corrosion and oxidation.
(B) Aluminum: Develops a robust, self-repairing aluminum oxide layer, providing excellent corrosion resistance.
(C) Copper: Slowly corrodes to form a protective patina.
(D) Tin: Resistant to water corrosion, but less resistant than aluminum or copper to other elements.
(A) Zinc: The most reactive, corroding easily. Used as a sacrificial coating for steel (galvanization) due to this property.

Step 2: Determine the sequence. The order from highest to lowest resistance is Gold, Aluminum, Copper, Tin, Zinc, corresponding to (E), (B), (C), (D), (A), which is option (2).