Osmotic potential(ψS) of a solution is always :

Options

A. Positive
B. Negative
C. Zero
D. Variable

Answer

**Step-by-Step Solution:**

1. **Understanding Osmotic Potential (ψS):**
- Osmotic potential (ψS) is a measure of the tendency of water to move into a solution due to the presence of solute particles. It is influenced by the concentration of solute in the solution.

2. **Types of Solutions:**
- There are two types of solutions to consider:
- A solution with solute (e.g., saltwater).
- A pure solvent (e.g., distilled water) which has no solute.

3. **Effect of Solute on Osmotic Potential:**
- In a solution with solute, the presence of solute particles displaces some of the solvent molecules. This displacement affects the movement of water molecules.

4. **Sign of Osmotic Potential:**
- The osmotic potential of a solution is always negative. This is because the presence of solute lowers the potential energy of the water in the solution compared to pure water, which is assigned a value of zero.

5. **Magnitude of Osmotic Potential:**
- The more solute particles present in a solution, the more negative the osmotic potential will be. Thus, there is a direct relationship between the concentration of solute and the magnitude of the negative osmotic potential.

6. **Conclusion:**
- Therefore, the osmotic potential (ψS) of any solution is always negative, indicating that it is a measure of the tendency of water to move into the solution.

**Final Answer:**
The osmotic potential (ψS) of a solution is always negative.

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