Which one of the following statements is not correct?

Options

A. Brownian movement is more pronounced for smaller particles than for bigger ones.
B. Sols of metal sulphides are lyophilic.
C. Hardy Schulze law states, the bigger the size of the ions, the greater is its coagulating power.
D. One would expect charcoal to adsorb chlorine more strongly than hydrogen sulphide.

Answer

To determine which statement is not correct, we will analyze each option provided in the question step by step.

### Step 1: Analyze Option 1
**Statement:** Brownian movement is more pronounced for smaller particles than for bigger ones.

**Analysis:** This statement is correct. Brownian motion refers to the random movement of particles suspended in a fluid, and it is more noticeable for smaller particles. This is because smaller particles are more easily influenced by the collisions with the molecules of the fluid.

### Step 2: Analyze Option 2
**Statement:** Sols of metal sulfides are lyophilic.

**Analysis:** This statement is incorrect. Sols of metal sulfides are actually lyophobic, meaning they do not have an affinity for the solvent. Lyophilic sols have a strong attraction to the solvent, which is not the case for metal sulfides.

### Step 3: Analyze Option 3
**Statement:** Hardy-Schulze law states that the bigger the size of the ions, the greater is its coagulating power.

**Analysis:** This statement is also incorrect. Hardy-Schulze law states that smaller ions have a greater coagulating power. Therefore, the statement that larger ions have greater coagulating power is not correct.

### Step 4: Analyze Option 4
**Statement:** One would expect charcoal to adsorb chlorine more strongly than hydrogen sulfide.

**Analysis:** This statement is correct. Charcoal has a higher adsorption capacity for gases like chlorine compared to hydrogen sulfide due to the nature of the interactions involved.

### Conclusion
After analyzing all the options, we find that the statements that are not correct are:
- Option 2: Sols of metal sulfides are lyophilic (this is incorrect; they are lyophobic).
- Option 3: Hardy-Schulze law states that the bigger the size of the ions, the greater is its coagulating power (this is incorrect; it states the opposite).

### Final Answer
The statements that are not correct are Option 2 and Option 3.

---