Why is solute potential always negative ? Explain `Psi_(w)=Psi_(s)+Psi_(p)`.

Explanation

### Step-by-Step Solution

1. **Understanding Solute Potential**:
- Solute potential, also known as osmotic potential, is a measure of the tendency of water to move into a solution due to the presence of solute. It is influenced by the concentration of solute in the solution.

2. **Why is Solute Potential Negative?**:
- In pure water, the solute potential is defined as zero because there are no solute particles present. When solute is added to water, it reduces the free energy of water molecules. The more solute that is added, the lower the free energy becomes, resulting in a negative value for solute potential.
- Therefore, solute potential is always negative because it reflects the decrease in water's free energy due to the presence of solute particles.
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