In the process of extraction of gold,
Roasted gold ore `+CN^(-)+H_2Ooverset(o_2)rarr[X]+OH^(-)`
`[X]+Znrarr[Y]+Au`
Identify the complexes [X] and [Y]

Options

A. (a) `X=[Au(CN)_2]^(-), Y=[Zn(CN)_4]^(2-)`
B. (b) `X=[Au(CN)_4]^(3-), Y=[Zn(CN)_4]^(2-)`
C. (c) `X=[Au(CN)_2]^(-), Y=[Zn(CN)_6]^(4-)`
D. (d) `X=[Au(CN)_4]^(-), Y=[Zn(CN)_4]^(2-)`

Answer

A

Explanation

Roasted gold are `+CN^(-)+H_2Ooverset(O_2)rarr[Au(CN)_2]^(-)+OH`
`[Au(CN)_2]^(-)+Znrarr[Zn(CN)_4]^(2-)`.