Extraction of gold and silver involves leaching with `CN^(-)`ion.silver is later recovered by:

Options

A. distillation
B. zone refining
C. displacement by `Zn`
D. liquation

Answer

C

Explanation

`4 Ag + 8 NaCN + 2 H_(2) O + O_(2)`
`rarr 4 Na [Ag (CN)_(2)] + 4 NaOH`
`2[Ag (CN)_(2)]^(-) (aq) + Zn (s)`
`rarr 2 Ag (s) + [Zn (CN)_(4)]^(2-) (aq)`