Question

Write the equation for the extraction of silver by leaching with sodium cyanide and show that the leaching process is a redox reaction.

Answer 1

Answer:

In the case of silver metal, the sulphide ore is treated with sodium cyanide. Sodium argentocyanide complex is formed which on treating with zinc metal gives silver.

Ag

2

S+4NaCN→2Na[Ag(CN)

2

]+Na

2

S

2Na[Ag(CN)

2

]+Zn→Na

2

[Zn(CN)

4

]+2Ag↓.