On adding few drops of dilutie `HCl` or `FeCl_(3)` to freshly precipitated ferric hydroxide a red coloured colloidal solution is obtained. The phenomenon is know as

Options

A. Peptisation
B. Dialysis
C. Protective action
D. Dissociation

Answer

To solve the question, we need to understand the process that occurs when dilute HCl or FeCl3 is added to freshly precipitated ferric hydroxide, resulting in a red-colored colloidal solution.

### Step-by-Step Solution:

1. **Understanding the Initial State**:
- Freshly precipitated ferric hydroxide (Fe(OH)3) is a solid precipitate. In this state, it is not dispersed in a liquid medium and does not exhibit colloidal properties.

2. **Adding Electrolytes**:
- When we add dilute HCl (hydrochloric acid) or FeCl3 (ferric chloride) to the precipitate, we introduce electrolytes into the system. These electrolytes can interact with the surface of the ferric hydroxide particles.

3. **Conversion to Colloidal Solution**:
- The addition of these electrolytes causes the precipitate to disperse into the solution, forming a colloidal solution. This is because the electrolytes help to stabilize the particles and prevent them from aggregating back into a larger solid form.

4. **Identifying the Phenomenon**:
- The process of converting a precipitate into a colloidal solution by the addition of an electrolyte is known as **peptization**. This term specifically refers to the stabilization of colloidal particles through the addition of an electrolyte.

5. **Conclusion**:
- Therefore, the phenomenon observed when adding dilute HCl or FeCl3 to freshly precipitated ferric hydroxide, resulting in a red-colored colloidal solution, is known as **peptization**.

### Final Answer:
The phenomenon is known as **peptization**.

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