Question

(a) For the reduction of a metal oxide, suggest a reducing agent other than carbon.
(b) Explain why an aqueous solution of sodium chloride is not used for the electrolytic extraction of sodium metal.

Answer 1

(a) Aluminium (Al) can be used as a reducing agent for the reduction of a metal oxide. This is generally used for reducing metal oxides such as manganese dioxide $\left(Mn{O}_2\right)$.

(b) If an aqueous solution of sodium chloride is used in electrolysis, sodium metal, formed at the cathode, will immediately react with water in the aqueous solution to form sodium hydroxide because sodium is a highly reactive metal. Hence, it is important to use molten sodium chloride and not its aqueous solution in electrolytic extraction.