Which of the following pairs of metals is purified by van Arkel method?
- Ga and In
- Zr and Ti
- Ag and Au
- Ni and Fe
Answer
(2) Zr and Ti
Solution
As per NCERT, the van Arkel method is used to remove all the oxygen and nitrogen present as impurity in metals like zirconium and titanium.
The crude metal forms a volatile iodide, which decomposes on a hot tungsten filament:
Zr + 2I2 ZrI4
ZrI4 Zr + 2I2
Answer: (2)