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Write chemical reactions taking place in the extracion of Aluminium from Bauxite ore .A. The concentration of ore is done by gravity separation method.B. molten mixture of aluminium oxide, cryolite or fluorspar is electrolysedC. impure aluminium is refined by liquationD. molten aluminium is obtained at cathode while fluorine is liberated at anode. |
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Answer» Correct Answer - B Purified `Al_(2)O_(3)` is mixed with `Na_(3)AlF_(6)` and `CaF_(2)` to improve conductivity of `Al_(2)O_(3)` and to lower than melting point. `Al_(2)O_(3) overset("electrolysis")to 2Al^(3+) + 3O^(2-)` At cathode `: AL^(3+)+3e^(-) to Al` At anode :` C + O^(2-) to CO + 2e^(-) ` `C+2O^(2-) to CO_(2) + 4e^(-)` |
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