Answers and Solutions

Answer

 Aluminum oxide (alumina), Al2O3, has a high melting point (over 2000C) and trying to electrolyze molten Al2O3 by itself would really be an energy intensive process. Aluminum oxide is "dissolved" in molten cryolite and the resulting solution has a melting point much closer to 1000C. Aluminum fluoride, AlF3, is added to the melt to further reduce the melting point. This requires a great deal less energy to keep the solution molten so that electrolysis can be done to reduce the aluminum in Al2O3 to aluminum metal.

Answer

Cryolite lowers the melting point of the ore and make it more conductive in nature so as to carry out electrolysis of the ore in Hall- Heroult process.

Answer

  1.To lower melting point of Alumina - So reduced energy consumption

  2.It also increases conductivity of the solution - Easier and faster electrolysis

  Cheers!!!

Answer

Elemental aluminium cannot be produced by the electrolysis of an aqueous aluminium salt because hydronium ions readily oxidize elemental aluminium. Although a molten aluminium salt could be used instead, aluminium oxide has a melting point of over 2,000 °C (3,600 °F) so electrolyzing it is impractical. In the Hall–Héroult process alumina, Al2O3, is dissolved in molten cryolite, Na3AlF6, to lower its melting point for easier electrolysis,it also increases conductivity of the solution.

Pure cryolite has a melting point of 1,012 °C (1,854 °F). With a small percentage of alumina dissolved in it, its melting point drops to about 1,000 °C (1,800 °F). Aluminium fluoride, AlF3 is added to the mixture to further reduce the melting point.

Answer

Aluminum oxide (alumina), Al2O3, has a high melting point (over 2000C) and trying to electrolyze molten Al2O3 by itself would really be an energy intensive process. Aluminum oxide is "dissolved" in molten cryolite and the resulting solution has a melting point much closer to 1000C. Aluminum fluoride, AlF3, is added to the melt to further reduce the melting point. This requires a great deal less energy to keep the solution molten so that electrolysis can be done to reduce the aluminum in Al2O3 to aluminum metal.