Ibn the cyanide extraction process of silver form aragetite are ,oxidizing and reduction agents used are action .

Options

A. `O_(2)` and CO
B. `O_(2)` and Zn dust
C. `HNO_(3)` and Zn dust
D. `HNO_(3)` and CO

Answer

B

Explanation

The reactions involved in the extraction of silver by cyanide process are
`Ag_(2)S+4CN^(-)+O_(2)rarr2[Ag(CN)_(2)]^(-)+SO_(2)" "...(i)`
`2[Ag(CN)_(2)]^(-)+Zn rarr[Zn(CN)_(4)]^(2-)+2Ag" "...(ii)`
In the first reaction, sulphide is oxidised by oxygen to `SO_(2)` and in the second reaction, silver ion is reduced by Zn to Ag. Therefore, `O_(2)` is oxidising agent and Zn is reducing agent.