Question

Which of the following metals is refined by using a tungsten filament for heating in a vessel so that the pure metal deposits on the filament?

• A. Cu
• B. Zr
• C. Al
• D. Ni

Hint:

The iodide (Van Arkel) process is used for ultra-purification of metals like zirconium and titanium.

Answer 1

The Correct Option is B

Step 1: Identify the refining method described.
The process described is the Van Arkel–de Boer (iodide) process.
In this method, an impure metal is converted into a volatile iodide and then decomposed on a hot tungsten filament to obtain pure metal.
Step 2: Recall metals purified by iodide process.
This method is used for refining metals like \(\mathrm{Zr}\) and \(\mathrm{Ti}\).
The metal iodide decomposes on the hot tungsten filament, depositing pure metal.
Step 3: Analyze the given options.
(A) Cu: Refined by electrolytic refining.
(B) Zr: Correct — refined by iodide process using tungsten filament.
(C) Al: Extracted by Hall–Héroult process.
(D) Ni: Refined by Mond process.
Step 4: Conclusion.
Zirconium is refined using a tungsten filament in the iodide process.