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प्रश्न
In the extraction of aluminium by Hall-Heroult process, purified \[\ce{Al2O3}\] is mixed with \[\ce{CaF2}\] to:
(i) lower the melting point of \[\ce{Al2O3}\].
(ii) increase the conductivity of molten mixture.
(iii) reduce \[\ce{Al^{3+}}\] into \[\ce{Al(s)}\].
(iv) acts as catalyst.
उत्तर
(i) lower the melting point of \[\ce{Al2O3}\].
(ii) increase the conductivity of molten mixture.
Explanation:
\[\ce{CaF2}\] mixed with purified \[\ce{Al2O3}\] helps in lowering the melting point of \[\ce{Al2O3}\] and increases the conductivity of the molten mixture.
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