Question

Electrochemical process is used in the extraction of which of the following?

• A. Sodium
• B. Iron
• C. Silver
• D. Gold

Hint:

Remember: Metals at the top of the reactivity series (Al and above) are extracted by electrolysis, while those in the middle are extracted by reduction with carbon.

Answer 1

The Correct Option is A

Concept: The method used to extract a metal from its ore depends primarily on the metal's position in the Reactivity Series. • High Reactivity Metals: (e.g., Na, K, Ca, Mg, Al) These metals are very stable in their compounds and cannot be reduced by common chemical reducing agents like Carbon (C) or Carbon Monoxide (CO). They require Electrolytic Reduction. • Medium Reactivity Metals: (e.g., Zn, Fe, Pb) These are usually extracted by chemical reduction using Carbon. • Low Reactivity Metals: (e.g., Ag, Au) These often occur in a free state or can be extracted through simple heating or leaching processes.
Sodium is a highly reactive alkali metal. It has a high affinity for oxygen and other non-metals, meaning its compounds are very stable. Reducing sodium oxide or chloride with carbon is not thermodynamically feasible because carbon is less reactive than sodium. Therefore, sodium is extracted by the electrolysis of molten sodium chloride (Down's Process).
• Iron (Fe): Extracted via chemical reduction in a Blast Furnace using coke (carbon). • Silver (Ag) and Gold (Au): These are noble metals. They are typically extracted via hydrometallurgy (cyanide process/leaching) or simply found in their native metallic state.