In extraction of gold, zinc acts as

Options

A. flux
B. oxidising agent
C. reudcing agent
D. none.

Answer

To answer the question "In extraction of gold, zinc acts as", we can break down the process step by step.

### Step-by-Step Solution:

1. **Understanding the Extraction Process**:
- Gold is extracted from its ore using the cyanide process, where gold is dissolved in a cyanide solution to form a complex ion.

2. **Formation of Gold Complex**:
- The reaction can be represented as:
\[ 4 \text{Au} + 8 \text{CN}^- + 2 \text{H}_2\text{O} + \text{O}_2 \rightarrow 4 \text{[Au(CN)}_2]^− + 4 \text{OH}^− \]
- Here, gold (Au) reacts with cyanide ions (CN^-) to form the complex ion \([Au(CN)_2]^−\).

3. **Role of Zinc**:
- Zinc is introduced to the solution containing the gold-cyanide complex. The reaction involving zinc can be represented as:
\[ 4 \text{[Au(CN)}_2]^- + \text{Zn} \rightarrow 4 \text{Au} + \text{[Zn(CN)}_4]^{2-} \]
- In this reaction, zinc reduces the gold complex back to elemental gold.

4. **Oxidation States**:
- In the reaction, zinc goes from an oxidation state of 0 (elemental zinc) to +2 in the complex \([Zn(CN)_4]^{2-}\).
- This indicates that zinc is losing electrons and is thus being oxidized.

5. **Identifying the Type of Agent**:
- Since zinc is oxidized (loses electrons), it acts as a reducing agent because it facilitates the reduction of the gold complex back to gold.

6. **Conclusion**:
- Therefore, in the extraction of gold, zinc acts as a **reducing agent**.

### Final Answer:
In the extraction of gold, zinc acts as a reducing agent.

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