Answer any seven questions of the following
Discuss van Arkel Boer method for ultrapurification of zirconium.

Explanation

In the van-Arkel method for ultra-purification of zirconium (Zr), the crude metal (Zr) is heated in evacuated vessel with iodine at about 870 K. Volatile `ZrI_(4)`, thus formed is passed through electrical arrangement at about 1800K, which decomposes `ZrI_(4)` and give pure Zr. (Tungsten filament)
`underset(("Impure"))(Zr(s)) + 2I_(2) (g) overset(870 K)rarr ZrI_(4)(g) overset("1800 K (Tungsten filament)")rarr underset(("Pure"))(Zr(s)) + 2I_(2)(g)`