Question 38
Metals and their CompoundsAluminium is extracted commercially from its ore by
- A.heating aluminium oxide with coke in a furnace
- B.the electrolysis of fused aluminium oxide in cryolite
- C.treating cryolite with sodium hydroxide solution under pressure
- D.heating sodium aluminium silicate to a high temperature.
Show the answer and explanation
Answer: B (the electrolysis of fused aluminium oxide in cryolite)
Explanation
Aluminium is too reactive to be reduced by carbon, so purified alumina dissolved in molten cryolite is electrolysed.