MCQ
In Hall’s process, the main reagent is mixed with
- A$NaF$
- ✓$N{a_3}Al{F_6}$
- C$Al{F_3}$
- DNone of these
✓
Answer
Correct option: B.
$N{a_3}Al{F_6}$
b
(b) Pure alumina is a bad conductor of electricity and the fusion temperature of pure alumina is about $2000\,^°C$ and at this temperature when the electrolysis is carried of fused mass the metal formed vapoureses as the boiling point of $Al$ is $1800\,^°C$.
To overcome this difficulty, $N{a_3}Al{F_6}$ and $Ca{F_2}$ are mixed with alumina.
(b) Pure alumina is a bad conductor of electricity and the fusion temperature of pure alumina is about $2000\,^°C$ and at this temperature when the electrolysis is carried of fused mass the metal formed vapoureses as the boiling point of $Al$ is $1800\,^°C$.
To overcome this difficulty, $N{a_3}Al{F_6}$ and $Ca{F_2}$ are mixed with alumina.
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