A negatively charged suspension of clay in water will need for precipitation the minimum amount of

Options

A. `AlCl_(3)`
B. `K_(2)SO_(4)`
C. NaOH
D. HCI

Answer

To solve the question regarding the minimum amount of electrolyte needed for the precipitation of a negatively charged suspension of clay in water, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Nature of the Suspension**:
- The suspension of clay in water is negatively charged. This means that the clay particles have a negative charge on their surface.

2. **Identify the Coagulating Agent**:
- To precipitate or coagulate the negatively charged clay particles, we need to introduce positively charged ions (cations) into the solution.

3. **Apply Hardy-Schulze Rule**:
- According to the Hardy-Schulze rule, the coagulating power of an electrolyte is directly proportional to the valency of the oppositely charged ion. This means that ions with higher valency will have a greater coagulating effect.

4. **Evaluate the Options**:
- We need to compare the valency of the available cations:
- **Al³⁺ (Aluminum ion)**: Valency = 3
- **K⁺ (Potassium ion)**: Valency = 1
- **Na⁺ (Sodium ion)**: Valency = 1
- **H⁺ (Hydrogen ion)**: Valency = 1

5. **Determine the Best Coagulating Ion**:
- Among the given options, Al³⁺ has the highest valency (3), which means it will have the strongest coagulating power compared to K⁺, Na⁺, and H⁺.

6. **Conclusion**:
- Therefore, the minimum amount of electrolyte required for the precipitation of the negatively charged suspension of clay in water will be the one containing Al³⁺ ions.

### Final Answer:
The correct answer is **Al³⁺ (Aluminum ion)**, as it has the highest coagulating power due to its higher valency.

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