`As_(2) S_(3)` Colloidal solution obtained when `As_(2) O_(3)` is
Saturated with `H_(2) S`. Which is the diffused part?

Options

A. `As^(+3)`
B. `S^(-2)`
C. `H^(+)`
D. `O^(-2)`

Answer

To solve the question regarding the diffused part in the colloidal solution of As₂S₃ obtained from As₂O₃ saturated with H₂S, we can follow these steps:

### Step 1: Understand the Reaction
The first step is to recognize the chemical reaction that occurs when As₂O₃ is saturated with H₂S. The reaction can be represented as:
\[ \text{As}_2\text{O}_3 + 3\text{H}_2\text{S} \rightarrow \text{As}_2\text{S}_3 + 3\text{H}_2\text{O} \]
This shows that arsenic oxide reacts with hydrogen sulfide to form arsenic sulfide and water.

**Hint:** Identify the reactants and products of the chemical reaction.

### Step 2: Identify the Colloidal Solution
From the reaction, we can see that As₂S₃ (arsenic sulfide) is formed as a colloidal solution. Colloidal solutions consist of particles that are dispersed in a continuous phase.

**Hint:** Recognize that the product of the reaction is the colloidal solution we are interested in.

### Step 3: Determine the Charge of the Colloidal Particles
In colloidal solutions, the charge of the particles plays a crucial role. In this case, As₂S₃ is a negatively charged sol. This negative charge arises from the adsorption of sulfide ions (S²⁻) on the surface of the As₂S₃ particles.

**Hint:** Consider how ions from the reactants can affect the charge of the colloidal particles.

### Step 4: Identify the Diffused Part
The term "diffused part" refers to the ions that are present in the solution and contribute to the charge of the colloidal particles. In this case, the sulfide ions (S²⁻) are adsorbed onto the surface of the As₂S₃ particles, making them the diffused part of the colloidal solution.

**Hint:** Focus on which ions are responsible for the charge in the colloidal solution.

### Conclusion
Based on the analysis, the diffused part in the colloidal solution of As₂S₃ obtained from As₂O₃ saturated with H₂S is the sulfide ion (S²⁻). Therefore, the correct answer is:

**Answer:** Option B, S²⁻.