Theoretically, water potential of the pure water is taken as

Options

A. Zero
B. 100
C. Negative
D. Positive

Answer

To determine the theoretical water potential of pure water, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Water Potential**: Water potential is defined as the potential energy of water in a system compared to pure water, and it influences the movement of water in plants. It is represented by the symbol Ψ (psi).

2. **Defining Pure Water**: Pure water is considered to have no solutes and is at atmospheric pressure. This means that it has the highest possible free energy.

3. **Water Potential of Pure Water**: The water potential of pure water is taken as the reference point. By definition, the water potential of pure water at standard conditions (atmospheric pressure) is set to zero.

4. **Comparing with Solutions**: When solutes are added to water, they decrease the free energy of the water molecules, leading to a negative water potential. Therefore, the water potential of solutions containing solutes will always be less than zero.

5. **Conclusion**: Since pure water has the highest free energy and no solutes, its water potential is theoretically equal to zero.

### Final Answer:
Theoretically, the water potential of pure water is taken as **0**.

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