Question

Explain in brief types of extraction of less reactive metals according to their reactivity.

Answer 1

Extraction of less reactive metals:

1. Less reactive metals such as gold, silver, platinum are found in a free state in nature.
2. However, the reserves of copper in the free state are very few. It is found mainly in the form of Cu₂S. Copper is obtained from Cu₂S ore just by heating in the air.
   \[\ce{\underset{\text{sulphide}}{\underset{\text{Copper(I)}}{2Cu2S_{(s)}}} + \underset{\text{Oxygen}}{3O_{2(g)}} ->[Heat] \underset{\text{oxide}}{\underset{\text{Copper(I)}}{2Cu2O_{(s)}}} + \underset{\text{dioxide}}{\underset{\text{Sulphur}}{2SO2\uparrow}}}\]
   
   \[\ce{\underset{\text{Copper(I) sulphide}}{Cu2S_{(s)}} + \underset{\text{Copper(I) oxide}}{2Cu2O_{(s)}} ->[Heat] \underset{\text{Copper}}{6Cu_{(s)}} + \underset{\text{Sulphur dioxide}}{SO_2\uparrow}}\]
3. The copper metal thus obtained can be further refined electrolytically.