Which among the following statement(s) is(are) true for the extraction of aluminum from bauxite?
Answers
Answer:
C) is True..........................
Which among the following statements is/are true for the extraction of aluminium from bauxite ?
(A) Hydrated Al2O3 precipitate, when CO2 is bubbled through a solution of sodium aluminate.
(B) addition of Na3AlF6 lower the melting point of alumina.
(C) CO2 is evolved at the anode during electrolysis.
(D) The cathode is a steel vessel with a lining of carbon.
solution : option (A) is correct choice, Hydrated Al2O3 precipitate, when CO2 is bubbled through a solution of sodium aluminate.
reaction is written as ...
2Na[Al(OH)₄] + CO₂ → Na₂O₃ + H₂O + 2Al(OH)₃ or Al₂O₃.2H₂O (↓)
option (B) is also correct, function of Na3AlF6 is to lower the melting point of electrolyte. but it also increase the conductivity of electrolye.
during electrolysis of Al2O3, The reaction at anode are [2Al³⁺ + 3O²¯ → O₂ + 2e¯ ] and C (graphite) + O₂ → CO(↑) + CO₂ (↑) , so option (C) is correct.
steel vessel with lining of carbons acts as cathode so option (D) is also correct choice.
Therefore All options are correct