Which of the following sols is positively charged?

Options

A. Arsenious sulphide
B. Aluminium hydroxide
C. Ferric hydroxide
D. Silver iodide in silver nitrate solution

Explanation

To determine which of the given sols is positively charged, we need to analyze each option based on their chemical nature and the charge they carry in solution.

### Step-by-Step Solution:

1. **Identify the options**: The options given are:
- A) Arsenic Sulfide (As₂S₃)
- B) Aluminum Hydroxide (Al(OH)₃)
- C) Ferric Sulfide (Fe₂S₃)
- D) Silver Iodide (AgI) in Silver Nitrate solution (AgNO₃)

2. **Analyze Arsenic Sulfide (As₂S₃)**:
- Arsenic sulfide is a metal sulfide. Metal sulfides generally carry a negative charge in colloidal form. Therefore, As₂S₃ is negatively charged.

3. **Analyze Aluminum Hydroxide (Al(OH)₃)**:
- Aluminum hydroxide is a metal hydroxide. Metal hydroxides tend to form positively charged colloids. Thus, Al(OH)₃ is positively charged.

4. **Analyze Ferric Sulfide (Fe₂S₃)**:
- Ferric sulfide is also a metal sulfide. Similar to arsenic sulfide, it carries a negative charge in colloidal form. Therefore, Fe₂S₃ is negatively charged.

5. **Analyze Silver Iodide (AgI) in Silver Nitrate solution (AgNO₃)**:
- Silver iodide can form a positively charged sol when in the presence of silver nitrate, which provides silver ions (Ag⁺). Thus, AgI in AgNO₃ is positively charged.

6. **Conclusion**:
- From the analysis, we find that:
- Arsenic Sulfide (A) is negatively charged.
- Aluminum Hydroxide (B) is positively charged.
- Ferric Sulfide (C) is negatively charged.
- Silver Iodide in Silver Nitrate solution (D) is positively charged.
- Therefore, the positively charged sols among the options are **B) Aluminum Hydroxide and D) Silver Iodide in Silver Nitrate solution**.

### Final Answer:
The positively charged sols are **B) Aluminum Hydroxide and D) Silver Iodide in Silver Nitrate solution**.

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