ACS Gen Chem Question

[dragonfruit95]

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in the study guide, there's a question that I don't understand and was wondering if someone could explain it.

Which is the most satisfactory solvent for alumina, Al2O3, in the electrolytic process for preparation of aluminum?

A) liquid water, H20
B) Molten Cryolite, Na3AlF6
C) Molten bauxite, Al2O3 with other oxides
D)Molten Sodium Chloride, NaCl

the answer was B

 

[DAT Destroyer]

in the study guide, there's a question that I don't understand and was wondering if someone could explain it.

Which is the most satisfactory solvent for alumina, Al2O3, in the electrolytic process for preparation of aluminum?

A) liquid water, H20
B) Molten Cryolite, Na3AlF6
C) Molten bauxite, Al2O3 with other oxides
D)Molten Sodium Chloride, NaCl

the answer was B

The extraction is done by electrolysis. But first the aluminium oxide must be melted so that electricity can pass through it. However, aluminium oxide has a very high melting point (over 2000°C) so it would be expensive to melt it. Instead, it is dissolved in molten cryolite - an aluminium compound with a lower melting point than aluminium oxide. The use of molten cryolite as a solvent reduces some of the energy costs involved in extracting aluminium.

Hope this helps.

Dr. Romano

 

[dragonfruit95]

Thank you so much, Dr. Romano!