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: Order the metals based on their corrosion resistance in a typical environment, from highest to lowest.

(E) Gold: As a noble metal, it is extremely inert and has the highest resistance to corrosion and oxidation.
(B) Aluminum: Forms a very tough, stable, and self-healing passive layer of aluminum oxide, giving it excellent corrosion resistance.
(C) Copper: Corrodes slowly to form a stable green patina that protects the underlying metal.
(D) Tin: Is quite resistant to corrosion from water but is less resistant than copper or aluminum to other elements.
(A) Zinc: Is the most reactive of the group and corrodes readily. This property is why it is used as a sacrificial coating for steel (galvanization).

Step 2: Form the sequence. The correct order from maximum to minimum resistance is Gold, Aluminum, Copper, Tin, Zinc. This corresponds to the sequence (E), (B), (C), (D), (A), which matches option (2).