Question

Which method of purification is represented by the following equation?

\[\ce{Ti + 2I2 ->[773 K] Til4 ->[1675 K] Ti + 2I2}\]

Options

• Cupellation

• Poling

• Van Arkel

• Zone refining

Answer 1

Van Arkel

Explanation:

The given reaction represents the Van Arkel method of purification. In this method, impure titanium (Ti) reacts with iodine (I₂) at about 773 K to form titanium tetraiodide (TiI₄), a volatile compound. On further heating at about 1675 K on a hot tungsten filament, (TiI₄) decomposes to give pure titanium and iodine. This method is used for refining metals like titanium and zirconium to a very high purity level by forming and decomposing their volatile iodides.