Cadmium sulphide sol has negative charge. The maximum power of coagulation is of:

Options

A. `H_(2)SO_(4)`
B. `Na_(3)PO_(4)`
C. `CaCI_(2)`
D. `AICI_(3)`

Answer

To solve the question regarding the maximum power of coagulation for cadmium sulphide sol, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Charge of the Sol**:
- Cadmium sulphide (CdS) sol has a negative charge.

2. **Understand the Hardy-Schulze Rule**:
- According to the Hardy-Schulze rule, ions that carry a charge opposite to that of the sol particles are effective in causing coagulation. Since CdS sol is negatively charged, we need to look for positively charged ions.

3. **Coagulation Power of Electrolytes**:
- The coagulation power of an electrolyte is directly proportional to the valency of the active ions. This means that ions with higher valency will have a greater ability to cause coagulation.

4. **Evaluate the Given Options**:
- The options provided are:
- H₂SO₄ (provides H⁺, +1 charge)
- NaCl (provides Na⁺, +1 charge)
- CaCl₂ (provides Ca²⁺, +2 charge)
- Al₂(SO₄)₃ (provides Al³⁺, +3 charge)

5. **Determine the Valency of the Ions**:
- H⁺ has a valency of 1.
- Na⁺ has a valency of 1.
- Ca²⁺ has a valency of 2.
- Al³⁺ has a valency of 3.

6. **Rank the Coagulation Power**:
- Based on the valency, we rank the ions:
- Al³⁺ (valency 3) > Ca²⁺ (valency 2) > Na⁺ (valency 1) = H⁺ (valency 1).

7. **Conclusion**:
- Since Al³⁺ has the highest valency, it will have the maximum power of coagulation for the negatively charged cadmium sulphide sol.

### Final Answer:
The maximum power of coagulation for cadmium sulphide sol is due to Al³⁺ ions.

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