Concept:Highly reactive metals, like alkali metals, are extracted by electrolysis of their molten compounds because they cannot be reduced by carbon or other chemical methods.
Explanation:Sodium (Na) is a highly reactive alkali metal. It is extracted from molten sodium chloride (NaCl) using the Downs Cell method.
In this process, an electric current passes through the molten salt. Sodium metal forms at the cathode, and chlorine gas is released at the anode.
The melting point of NaCl is lowered by adding calcium chloride (
CaCl2​) to make the process efficient.
Copper (Cu) is extracted by smelting and roasting its ores. Electrolysis is only used for refining copper, not for extraction.
Gold (Au) occurs in native form and is extracted by cyanidation or amalgamation, not by electrolysis of a molten compound.
Tin (Sn) is extracted from cassiterite (
SnO2​) by reduction with carbon in a furnace, not by electrolysis.
Only sodium requires the strong driving force of electrolysis because of its high reactivity.
Answer:D. Na