Question

In which of the following method of purification, metal is converted to its volatile compound which is decomposed to give pure metal?

• A. Heating with stream of carbon monoxide
• B. Heating with iodine
• C. Liquation
• D. Distillation

Answer 1

Answer: (A), (B)

Heating with stream of carbon monoxide
Heating with iodine

Vapor phase refining or purification method includes:

(i) Mond's process - Heating of metal with stream of $CO$ :

$Ni+4CO\to Ni(CO{)}_4\stackrel{\text{450-470 K}}{\to }Ni+4CO$

(ii) Van Arkel method - Heating with iodine:

$Zr+2I_2\stackrel{\text{870K}}{\to }Zr{I}_4\stackrel{\text{2000 K}}{\to }Zr+2I_2$

Hence, the correct options are (A) and (B).