During the extraction of gold the following reactions takes place
`Au+CN^(-) +H_(2)Orarr X,Y +ZnrarrY+Au`
Here, `X`and `Y` respectively are

Options

A. `[Au(CN)_(4)]^(2-)`and`[Zn(CN)_(6)]^(4-)`
B. `[Au(CN)_(4)]^(3-)`and`[Zn(CN)_(4)]^(2-)`
C. `[Au(CN)_(4)]^(2-)`and`[Zn(CN)_(4)]^(2-)`
D. `[Au(CN)_(2)]^(-)`and`[Zn(CN)_(4)]^(2-)`

Answer

D

Explanation

`4Au(s) +8CN^(-)(aq)+2H_(2)O(aq)`
`overset(O_(2))rarr4[Au(CN)_(2)] +4OH^(-)(aq)`
`2[Au(CN)_(2)](q) +Zn(s) rarr [Zn(CN)_(4)]^(2-)(aq) +2Au(s)`