Match List-I and List-II. Select the correct answer using the codes given below the list:
List-I (Metal)
a) Ni
b) Cu
c) Zr
d) Ge
List-II (Name of the refining process)
1. Van Arkel process
2. Electrolysis
3. Mond process
4. Zone refining

Correct option is D

The correct answer is (d) a-3, b-2, c-1, d-4

Explanation:
• Nickel (Ni) is refined by the Mond process involving the formation of volatile nickel carbonyl.
• Copper (Cu) is refined by Electrolysis (electrolytic refining).
• Zirconium (Zr) and Titanium are refined by the Van Arkel process (Vapor phase refining).
• Germanium (Ge) and Silicon are refined by Zone refining to obtain ultra-pure semiconductors.

Information Booster:
• The Mond process uses Carbon Monoxide (CO) to form $Ni(CO)_4$.
• Zone refining is based on the principle that impurities are more soluble in the melt than in the solid state.

Additional Knowledge:
Option A
• Incorrectly matches Ni with Van Arkel.
Option B
• Incorrectly matches Ni with Electrolysis.
Option C
• Incorrectly matches Ni with Zone refining.

So the correct answer is (d)