Question

Give reasons for the following:
Carbonate and sulphide ores are usually converted into oxides during the process of
extraction of metals.
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Answer 1

Answer:

This is because it is easier to reduce metals from their oxides rather than carbonates or sulphides.

Explanation:

Examples:

1. Sulphide ore

ZnS + O₂ --------> ZnO + SO₂ (roasting)

2. Carbonate ore

ZnCO₃ -----heat---------> ZnO + CO₂ (calcination)

Now,

ZnO + C ----------> Zn + CO (smelting)

ZnO + CO -------> Zn + CO₂ (sometimes carbon-dioxide is also used)

ZnO + 2Na --------> Zn + Na₂O (a metal of higher reactivity can also be used)

These were the ways in which Zn can be extracted from its sulphide or carbonate ores.

Answer 2

Answer:

The carbonates and sulphides are first oxidised in order to easily reduce them to respective metals..

Hope it helps ..........