Which one of the following statements is/are not correct ?

Options

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

Explanation

To determine which statements are not correct, we will analyze each option one by one.

### Step-by-Step Solution:

1. **Option 1: Brownian movement is more pronounced for smaller particles than for bigger ones.**
- **Analysis:** Brownian movement refers to the random motion of particles suspended in a fluid, caused by collisions with fast-moving molecules in the fluid. It is indeed true that smaller particles experience more pronounced Brownian movement because they are less affected by the viscous drag of the fluid. Thus, this statement is **correct**.

2. **Option 2: Souls of metal sulphides are lyophilic.**
- **Analysis:** Lyophilic colloids are those that have an affinity for the solvent, while lyophobic colloids do not. Metal sulphides are known to be lyophobic, meaning they repel the solvent. Therefore, this statement is **incorrect**.

3. **Option 3: The greater the size of the iron, the greater is its coagulating power.**
- **Analysis:** The coagulating power of a substance depends on its charge rather than its size. Larger particles do not necessarily have greater coagulating power; instead, it is the charge that plays a crucial role. Thus, this statement is **incorrect**.

4. **Option 4: One would expect charcoal to adsorb hydrogen gas more strongly than chlorine.**
- **Analysis:** Charcoal is known to adsorb chlorine gas more effectively than hydrogen gas. This is because chlorine is more easily polarizable than hydrogen, and it has a larger surface area for adsorption. Therefore, this statement is **incorrect**.

### Summary of Findings:
- **Correct Statements:** Option 1
- **Incorrect Statements:** Option 2, Option 3, Option 4

### Conclusion:
The statements that are not correct are **Option 2, Option 3, and Option 4**.

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