Which of the following anions will have minimum flocculation value for the ferric oxide solution?

Options

A. `Cl^(-)`
B. `Br^(-)`
C. `SO_(4)^(2-)`
D. `[Fe(CN)_(6)]^(3-)`

Answer

To determine which anion has the minimum flocculation value for a ferric oxide solution, we need to understand the relationship between flocculation value and coagulating power.

### Step-by-Step Solution:

1. **Identify the Charge of Ferric Oxide**:
Ferric oxide (Fe₂O₃) is a positively charged colloid. This means that in order to coagulate or flocculate the particles, we need to introduce negatively charged ions (anions).

2. **Understand Flocculation Value**:
The flocculation value refers to the concentration of anions required to cause flocculation. A lower flocculation value indicates a higher coagulating power of the anion.

3. **Coagulating Power and Flocculation Value Relationship**:
The flocculation value is inversely proportional to the coagulating power of the anions. This means that if an anion has a high coagulating power, it will have a low flocculation value.

4. **Analyze the Given Anions**:
We need to compare the coagulating power of the given anions. The coagulating power can be inferred from the charge of the anions. Typically, anions with higher negative charges have greater coagulating power.

5. **List the Anions and Their Charges**:
- Anion A: Charge -1
- Anion B: Charge -1
- Anion C: Charge -1
- Anion D: Charge -3 (Fe(CN)₆³⁻)

6. **Determine Coagulating Power**:
Since Anion D has a charge of -3, it has the highest coagulating power among the options provided. The other anions have a charge of -1, which means they have lower coagulating power.

7. **Conclusion**:
Since Anion D (Fe(CN)₆³⁻) has the highest coagulating power, it will have the minimum flocculation value. Therefore, the correct answer is option D.

### Final Answer:
The anion that will have the minimum flocculation value for the ferric oxide solution is **Option D (Fe(CN)₆³⁻)**.