$TiI_{4}$ on heating gives

Which method of purification is represented by the following equation?
$Ti_{(s)} + 2I_{2(g)}$ $\xrightarrow{523 \ K} TiI_{4(g)}$ $\xrightarrow{1700 \ K} Ti_{(s)} + 2I_{2(g)}$

Poling is employed in the refining of:

Impure aluminium is purified by

Which of the following methods is useful for producing semiconductor grade metals of high purity?

Identify the statements which are not correct.
$a)$ Copper is refined by Van-Arkel method
$b)$ Zinc is refined by electrolysis method
$c)$ Zirconium is refined by distillation method