Question

Which of the following involves electrolysis?

• A. Hall-Heroult process
• B. Van Arkel method
• C. Mond process
• D. Solvay process

Hint:

{Electrometallurgy:} Extraction of highly electropositive metals (Na, K, Mg, Al) is usually done by electrolysis of their fused salts.

Answer 1

The Correct Option is A

Step 1: Analyze each process:

• (A) Hall-Heroult process: Used for the extraction of Aluminium. It involves the electrolysis of fused mixture of alumina ($Al_2O_3$) and cryolite ($Na_3AlF_6$). This fits the description.
• (B) Van Arkel method: Used for refining Zirconium (Zr) or Titanium (Ti). It is a vapour phase refining process (formation and decomposition of iodide). No electrolysis.
• (C) Mond process: Used for refining Nickel (Ni). It involves the formation of volatile nickel tetracarbonyl and its subsequent thermal decomposition. No electrolysis.
• (D) Solvay process: Used for the manufacture of Sodium Carbonate ($Na_2CO_3$). It involves chemical precipitation reactions (using brine, ammonia, $CO_2$). No electrolysis.

Step 2: Conclusion:
Only the Hall-Heroult process uses electrolysis.