In the process of extraction of gold.
Roasted gold ore `+CN^(-)+H_(2)O overset(O_(2))rarr [X]+OH^(-)`
`[X]+Znrarr [Y]+Au`
Identify the complexes `[X] ` and `[Y]`.

Options

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

Answer

To solve the question regarding the extraction of gold and identify the complexes [X] and [Y], let's break down the reactions step by step.

### Step 1: Identify the reaction of roasted gold ore with cyanide and water in the presence of oxygen.

The roasted gold ore reacts with cyanide ions (CN^(-)) and water (H2O) in the presence of oxygen (O2). This reaction leads to the formation of a gold cyanide complex and hydroxide ions (OH^(-)).

The reaction can be represented as:
\[ \text{Roasted gold ore} + \text{CN}^- + \text{H}_2\text{O} + \text{O}_2 \rightarrow [X] + \text{OH}^- \]

The complex formed here is known as the **dicyanoaurate complex**. The formula for this complex is:
\[ [X] = \text{Au(CN)}_2^- \]

### Step 2: Identify the reaction of complex [X] with zinc.

The next step involves the reaction of the dicyanoaurate complex with zinc (Zn). Zinc is more reactive than gold and can displace gold from its complex. The reaction can be represented as:
\[ [X] + \text{Zn} \rightarrow [Y] + \text{Au} \]

In this reaction, the zinc displaces gold from the dicyanoaurate complex, forming a **zinc cyanide complex**. The formula for this complex is:
\[ [Y] = \text{Zn(CN)}_4^{2-} \]

### Conclusion

Thus, we can summarize the complexes as follows:
- Complex [X] is \(\text{Au(CN)}_2^-\) (dicyanoaurate complex).
- Complex [Y] is \(\text{Zn(CN)}_4^{2-}\) (tetracyanozinc complex).

### Final Answer
- Complex [X] = \(\text{Au(CN)}_2^-\)
- Complex [Y] = \(\text{Zn(CN)}_4^{2-}\)