Q.Which of the following metals is not obtained by electrolysis?

Highly reactive Na, Mg and Al are won by electrolysis, but iron is extracted by reduction with carbon in the blast furnace.

Strongly electropositive metals (Na, Mg, Al) cannot be reduced by ordinary chemical reducing agents, so they are obtained by electrolysis:

• Na: electrolysis of molten NaCl (Down's process)
• Mg: electrolysis of molten MgCl2
• Al: electrolysis of Al2O3 dissolved in molten cryolite (Hall-Heroult process) …

Na, Mg and Al are obtained by electrolysis; iron is obtained by reduction with carbon, not by electrolysis.

Highly reactive metals cannot be reduced by carbon, so they are extracted by electrolysis of their fused compounds:

• Na: electrolysis of molten NaCl (Down's process)
• Mg: electrolysis of molten MgCl2
• Al: electrolysis of alumina dissolved in molten cryolite (Hall-Heroult) …

Highly reactive metals cannot be reduced by carbon or chemical reducing agents; they are obtained by electrolysis of their fused salts. Sodium is such a metal.

Electrometallurgy = extraction of a metal by electrolytic reduction. It is used for the most reactive metals (Na, K, Ca, Mg, Al) whose oxides/chlorides cannot be reduced by carbon or CO.

…

Highly reactive metals Na, Mg, Al are obtained by electrolysis; iron is obtained by reduction of its oxide with carbon (coke) in the blast furnace.

Strongly electropositive metals cannot be reduced by carbon and are extracted by electrolysis of their molten salts/oxides:

• Na — electrolysis of molten NaCl (Down's process).
• Mg — electrolysis of molten MgCl2. …