Carbon cannot reduce the oxides of sodium, magnesium and aluminium to their respective metals. Why ? Where are these metals placed in the reactivity series? How are these metals. obtained from their ores ? Take an example to explain the process of extraction along with chemical equations.

Explanation

• This is because magnesium and aluminium lie higher than carbon in the activity series. Elements lying lower in activity series cannot reduce oxides of elements lying higher in the activity series.
• These metals are placed higher in the activity series.
• These metals are obtained by electrolytic reduction.
• For example, sodium is obtained by electrolysis of molten sodium chloride.
At cathode : `Na^(+) + e^(-)rarrNa`
At anode : `2Cl^(-)rarrCl_2 + 2e^(-)`