As the solute concentration in a solution increases, the change that does not occur is

Options

A. `pi` is more negative
B. `Psi` is more negative
C. `pi` becomes more positive
D. more influx of water

Answer

To solve the question "As the solute concentration in a solution increases, the change that does not occur is," we need to analyze the effects of increasing solute concentration on the properties of the solution, particularly the water potential (Ψ).

### Step-by-Step Solution:

1. **Understanding Water Potential (Ψ)**:
- Water potential (Ψ) is a measure of the potential energy of water in a solution. It determines the direction of water movement.
- Water potential is influenced by solute concentration and pressure. It is expressed in terms of pressure potential (Ψp) and solute potential (Ψs).

2. **Effect of Increasing Solute Concentration**:
- When solute concentration increases (for example, adding sugar to water), the solute potential (Ψs) becomes more negative. This is because the presence of solute particles reduces the availability of water molecules to do work.
- Therefore, as more solute is added, the overall water potential (Ψ) of the solution decreases (becomes more negative).

3. **Analyzing the Options**:
- **Option 1: Ψ becomes more negative** - This is true because increasing solute concentration decreases water potential.
- **Option 2: Ψ becomes more positive** - This is false. As solute concentration increases, water potential does not become more positive; it becomes more negative.
- **Option 3: More influx of water** - This is true because a higher concentration of solute attracts more water to the area of higher solute concentration (osmosis).
- **Option 4: Ψ is more positive** - This is also false for the same reason as option 2.

4. **Conclusion**:
- The change that does not occur as the solute concentration increases is that "Ψ becomes more positive." Therefore, the correct answer is that Ψ does not become more positive.

### Final Answer:
The change that does not occur is: **Ψ becomes more positive.**