P Block Elements Question 250
Question: In Hall’s process, the main reagent is mixed with
[AFMC 2005]
Options:
A) NaF
B) $ Na_3AlF_6 $
C) $ AlF_3 $
D) None of these
Show Answer
Answer:
Correct Answer: B
Solution:
Pure alumina is a bad conductor of electricity and the fusion temperature of pure alumina is about $ 2000{}^\circ C $ and at this temperature when the electrolysis is carried of fused mass the metal formed vapoureses as the boiling point of Al is $ 1800{}^\circ C $ . To overcome this difficulty, $ Na_3AlF_6 $ and $ CaF_2 $ are mixed with alumina.
BETA
