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

To solve the question of selecting the incorrect statement regarding diffusion, we will analyze each statement provided in the options.

### Step 1: Understand the concept of diffusion
Diffusion is defined as the movement of molecules from an area of higher concentration to an area of lower concentration. This process occurs without the expenditure of energy and continues until equilibrium is reached, meaning that the concentration of molecules is equal on both sides.

**Hint:** Remember that diffusion is a passive process that relies on concentration gradients.

### Step 2: Analyze the first statement
The first statement is: "Larger the difference in concentration, slower is the flow of molecules."
- This statement is incorrect. In fact, a larger difference in concentration (or concentration gradient) results in a faster rate of diffusion. The greater the difference, the more rapid the movement of molecules.

**Hint:** Think about how a steep hill (large difference) makes it easier for a ball to roll down quickly.

### Step 3: Analyze the second statement
The second statement is: "Diffusion is more rapid in gases than in liquids."
- This statement is correct. Diffusion occurs more quickly in gases due to the larger spaces between gas molecules, allowing them to move freely and collide more often compared to liquids.

**Hint:** Consider the movement of particles in different states of matter.

### Step 4: Analyze the third statement
The third statement is: "When there is no net movement of molecules, a state of equilibrium is reached."
- This statement is also correct. At equilibrium, the concentration of molecules is uniform throughout, and there is no net movement in one direction.

**Hint:** Equilibrium means balance; think about a seesaw that is perfectly level.

### Step 5: Analyze the fourth statement
The fourth statement is: "Diffusion is a random movement of molecules."
- This statement is correct as well. The movement of molecules during diffusion is random, as they move in all directions until equilibrium is achieved.

**Hint:** Visualize how people move around in a crowded room; their paths are unpredictable.

### Conclusion
After analyzing all the statements, the first statement is the only incorrect one. Therefore, the answer to the question is:

**Answer:** The incorrect statement is: "Larger the difference in concentration, slower is the flow of molecules."