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In the electrolysis of alumina, cryolite is added toA. Lower the melting point of aluminaB. Increase the electrical conductivityC. Minimise the anode effectD. Remove the impurities from alumina |
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Answer» Correct Answer - A::B The electrolysis of pure alumina faces some difficulties. Pure alumina is a bad conductor is of electricity. This fusion temperature of pure alumina is about `2000^@C`, and at this temperature, when the electrolysis is carried out on the fused mass, the metal formed vaporises as the boiling point aluminium is `1800^@ C`. These difficulties are overcome by using a mixture containing alumina, cryolite `(Na_(3)AlF_(6))`, and fluorpar `(CaF_(2))`. |
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