In the process of extraction of gold
Roasted gold ore `+CN^(-)+H_(2)Ooverset(O_(2))to[X]+OH^(-)`
`[X]+Znto[Y]+`Identify the complexes [X] and [Y]

Options

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

Answer

A

Explanation

`2Au + 4CN^(-) + H_(2)O +(1)/(2)O_(2)to2[Au(CN)_(2)]^(-)+20H^(-)`
`2[Au(CN)_(2)]^(-) + Zn to[Zn(CN)_(4)]^(2-)+2Au`
Hence, (A) is the correct answer. . . . .