Alkaline corrosion resistance is highest in____________________?
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Answer: B. Nickel
Explanation
Nickel forms a stable, passivating surface oxide layer that protects it from caustic chemical attacks. Its chemical stability prevents caustic soda and other strong alkaline solutions from dissolving the metal. This unique chemical inertness makes nickel superior in highly basic industrial processing environments. Alkaline substances have a pH value greater than seven, characterized by high hydroxide ion concentrations. Nickel is a versatile transition metal known for its silvery-white appearance and corrosion resistance. Caustic soda solutions refer specifically to concentrated aqueous solutions of sodium hydroxide.
Chemical manufacturing plants use nickel equipment for handling concentrated caustic soda and chlorine. Battery manufacturing facilities utilize nickel components to withstand highly alkaline electrolyte solutions. Food processing equipment often incorporates nickel alloys to resist cleaning chemicals and organic bases. Duriron is a high-silicon iron alloy excellent for resisting acids, but less effective against strong alkalis. Aluminium reacts vigorously with strong alkaline solutions, causing rapid corrosion and hydrogen gas evolution. Karbate is an impervious graphite material used for acids, but nickel is preferred for pure alkalis.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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