Question

Assertion : van Arkel method is used for refining of zinc.
Reason : In this method impure metal is evaporated to obtain the pure metal as distillate.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (D)

van Arkel method is used for refining of zirconium or titanium.
In this method crude metal is heated in an evacuated vessel with iodine.
$\underset{\text{ Impure }}{\mathrm{Zr}}+2I_2\stackrel{\Delta }{\to }Zr{I}_4$
The metal iodide is decomposed on tungsten filament, and pure metal is deposited on the filament.
$Zr{I}_4\stackrel{\Delta }{\to }\underset{\text{ pure }}{\mathrm{Zr}}+2I_2$