Gold is extracted by hydrometallurgical procees based on its property

Options

A. Of being electropositive
B. To form complexes, which are water soluble
C. Of being less reaction
D. To form salts, which are water soluble

Answer

**Step-by-Step Solution:**

1. **Understanding Gold's Properties:**
- Gold (Au) is known for being an inert metal, meaning it does not easily react with other substances. This property is crucial in its extraction process.

2. **Defining Hydrometallurgy:**
- Hydrometallurgy is a method used in extractive metallurgy that involves the use of aqueous solutions to recover metals from their ores. This process is particularly useful for metals like gold.

3. **Formation of Water-Soluble Complex:**
- In the hydrometallurgical process for gold extraction, gold metal reacts with a chemical (usually cyanide) to form a water-soluble complex. This is a key step in the extraction process.

4. **Chemical Reaction:**
- The reaction can be represented as follows:
\[ \text{Au (s)} + \text{CN}^- \rightarrow \text{[Au(CN)_2]}^- \]
- Here, the gold metal reacts with cyanide ions to form the complex ion \([Au(CN)_2]^-\), which is soluble in water.

5. **Conclusion:**
- The property of gold to form water-soluble complexes is utilized in the hydrometallurgical process for its extraction. Therefore, the answer to the question is that gold is extracted based on its ability to form soluble complexes.

**Final Answer:**
Gold is extracted by hydrometallurgical process based on its property to form water-soluble complexes.

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