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The major role of flourspar, `CaF_(2)` which is added in small amount in the electrolytic reduction of `Al_(2)O_(3)` dissolved on fused cryolite in fused cryolite isA. As a catalystB. To make the used mixture very conductingC. To increase the temperature of the meltD. To decrease the rate of oxidation of carbon of carbon at the anode |
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Answer» Correct Answer - B The electrolysis of puer alumina faces some difficulties. Pure alumina is a bad conductor of electricity. The fusion temperature of pure alumina is about `2000^@ C`. At this temperature when electrolysis is carried out on the fused mass, the metal formed valporises, as the boiling point of aluminium is `1800^@ C`. These difficulties are overcome by using a mixture containing alumina, aryolite `(na_(3)AlF_(6))`, and fluorspar `(CaF_(2))`. |
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