Select incorrect statement for diffusion

Options

A. Larger the difference in concentration, slower is the flow of molecules.
B. Diffusion is more rapid in gases than in liquids
C. When there is no net movement of molecules, a state of equilibrium is reached
D. Diffusion is a random movement of molecules

Answer

### Step-by-Step Solution:

1. **Understanding Diffusion**:
- Diffusion is defined as the movement of ions or molecules from a region of higher concentration to a region of lower concentration. This process occurs until equilibrium is reached.

2. **Key Characteristics of Diffusion**:
- **Concentration Gradient**: Molecules move along the concentration gradient, meaning they move from areas of high concentration to areas of low concentration.
- **Random Movement**: The movement of diffusing molecules is random.
- **Medium of Diffusion**: Diffusion occurs more rapidly in gases than in liquids due to the greater space between gas molecules, allowing them to move more freely.
- **Rate of Diffusion**: The greater the difference in concentration (the concentration gradient), the faster the rate of diffusion.

3. **Analyzing the Statements**:
- **Statement 1**: "The larger the difference in concentration, the slower is the flow of molecules."
- This statement is incorrect because a larger concentration difference actually leads to a faster rate of diffusion.
- **Statement 2**: "Diffusion is more rapid in gases than in liquids."
- This statement is correct.
- **Statement 3**: "When there is no net movement of molecules, a state of equilibrium is reached."
- This statement is correct.
- **Statement 4**: "Diffusion is a random movement of molecules."
- This statement is also correct.

4. **Conclusion**:
- The incorrect statement regarding diffusion is Statement 1, as it contradicts the fundamental principle of diffusion where a larger concentration gradient results in a faster rate of diffusion.

### Final Answer:
The incorrect statement for diffusion is: **"The larger the difference in concentration, the slower is the flow of molecules."**

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