select incorrect statement :

Options

A. gold sol is multimolecular colloid
B. large number of particles of a substance aggregate together and formed multimolecular colloids
C. Metal sulphides are lyophobic colloids
D. sulphur sol is multimolecular colloid oand hydrophilic in nature

Answer

To solve the question of selecting the incorrect statement regarding colloids, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Option 1: Gold sol is a multi-molecular colloid.**
- **Analysis:** Gold sol is indeed a colloidal solution where gold particles are dispersed in a liquid. Since it consists of a large number of small particles, it qualifies as a multi-molecular colloid.
- **Conclusion:** This statement is **true**.

2. **Option 2: Large number of particles of a substance aggregate together and form a multi-molecular colloid.**
- **Analysis:** This statement describes the formation of multi-molecular colloids accurately. Multi-molecular colloids are formed when many small particles aggregate together.
- **Conclusion:** This statement is **true**.

3. **Option 3: Sulfides are lipophobic colloids.**
- **Analysis:** Lipophobic colloids are those that do not interact well with lipids or oils. Metal sulfides generally do not mix with oils and are considered lipophobic.
- **Conclusion:** This statement is **true**.

4. **Option 4: Sulfur sol is a multi-molecular colloid and hydrophilic in nature.**
- **Analysis:** While it is correct that sulfur sol is a multi-molecular colloid, it is incorrect to state that it is hydrophilic. Sulfur sol is actually hydrophobic, meaning it does not interact well with water.
- **Conclusion:** This statement is **false**.

### Final Answer:
The incorrect statement is **Option 4**: "Sulfur sol is a multi-molecular colloid and hydrophilic in nature."

---