Question 39
Metals and their CompoundsIn the electrolytic extraction of aluminium, the function of the molten cryolite is to
- A.precipitate aluminium hydroxide
- B.lower the melting point of aluminium oxide
- C.act as a raw material
- D.act as a solvent
Show the answer and explanation
Answer: B (lower the melting point of aluminium oxide)
Explanation
Alumina melts above 2000 °C; dissolving it in cryolite lowers the working temperature to about 950 °C, saving energy.