Arsenic sulphide sol is prepared by passing `H_2S` through `As_2O_3` solution . The charge developed on sol particles is due to the adsorption of

Options

A. `H^+`
B. `S^(2-)`
C. `OH^(-)`
D. `O^(2-)`

Answer

To solve the question regarding the charge developed on arsenic sulfide sol particles due to the adsorption process, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Preparation of Arsenic Sulfide Sol:**
- Arsenic sulfide sol is prepared by passing hydrogen sulfide (H₂S) through a solution of arsenic trioxide (As₂O₃). This reaction leads to the formation of arsenic sulfide (As₂S₃) and water (H₂O).

2. **Identifying the Reaction:**
- The chemical reaction can be represented as:
\[ As_2O_3 + 3H_2S \rightarrow As_2S_3 + 3H_2O \]

3. **Understanding the Concept of Adsorption:**
- In colloidal systems, particles can acquire a charge due to the adsorption of ions from the surrounding medium. This phenomenon is crucial in determining the stability and behavior of colloidal sols.

4. **Identifying the Common Ion:**
- The common ion in this case is the sulfide ion (S²⁻) which is derived from the dissociation of hydrogen sulfide (H₂S) in the solution. The preferential adsorption of these ions onto the surface of the colloidal particles leads to the development of a charge.

5. **Charge Development on Sol Particles:**
- As the S²⁻ ions are adsorbed onto the surface of the arsenic sulfide particles, they impart a negative charge to the particles. This negative charge is crucial for the stability of the colloidal sol, as it prevents the particles from aggregating.

6. **Conclusion:**
- Therefore, the charge developed on the sol particles is primarily due to the adsorption of sulfide ions (S²⁻).

### Final Answer:
The charge developed on the sol particles is due to the adsorption of **sulfide ions (S²⁻)**.

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