Which one of the following metals can be extracted using carbon as reducing agent?

The Correct answer is Zinc.

Key Points

• Zinc can be extracted using carbon as a reducing agent in a process known as reduction. In metallurgy, carbon, often in the form of coke, is used to reduce metal oxides to pure metal by removing oxygen.
• The extraction process for zinc involves heating zinc oxide (ZnO) in the presence of carbon (C). The chemical reaction is:
  • ZnO(s) + C(s) → Zn(s) + CO(g)
• This method is effective because zinc is moderately reactive, and carbon acts as a strong reducing agent capable of removing oxygen from zinc oxide at high temperatures.
• Blast furnaces are often used for this reduction process, where the temperature is sufficiently high to facilitate the reaction between zinc oxide and carbon.
• The conversion of zinc oxide to zinc metal and carbon monoxide illustrates the fundamental principles of redox reactions (reduction-oxidation), where carbon is oxidized and zinc is reduced.

Additional Information

• Silver: It is typically extracted through hydrometallurgical or pyrometallurgical processes like leaching and smelting. Carbon is generally not used as a reducing agent for silver extraction.
• Gold: This noble metal is extracted via hydrometallurgy methods such as cyanidation. Due to its low reactivity, carbon plays no role in gold extraction processes.
• Aluminum: Extracted from bauxite ore through the Hall-Héroult process, which involves electrolysis of molten alumina. Carbon cannot reduce aluminum oxide effectively due to aluminium's high reactivity.
• The choice of reducing agent in metal extraction primarily depends on the metal's reactivity. Less reactive metals can be reduced using carbon, whereas more reactive metals require electrolytic reduction.