Question
Which statement about the extraction of aluminium is correct?
A. Aluminium is formed at the cathode during the electrolysis of aluminium oxide.
B. Hematite is mainly aluminium oxide.
C. Molten cryolite is used to raise the melting point of the aluminium oxide.
D. Oxygen gains electrons at the anode during the electrolysis of aluminium oxide.
Answer/Explanation
Ans:
A
Question
In the extraction of aluminum by electrolysis, cryolite is added to the bauxite ore.
Which row describes the role of cryolite and gives the ionic half-equation at the cathode?
Answer/Explanation
Ans:
C
Question
Why is cryolite used in the extraction of aluminium from bauxite?
A as a catalyst for the process
B as a solvent for aluminium oxide
C it stops the carbon anodes burning away
D it reduces aluminium ions in aluminium oxide
Answer/Explanation
Ans: B
Question
Which substances are used in the extraction of aluminium?
A bauxite and cryolite
B bauxite and hematite
C cryolite and zinc blende
D hematite and zinc blende
Answer/Explanation
Ans: A