1. What is Solute Potential?

Solute potential (Ψ_s) is the component of water potential that results from the presence of solute particles. It is always negative or zero and represents the reduction in water potential due to dissolved solutes.

2. How Does the Calculator Work?

The calculator uses the solute potential equation:

Where:

• \( \Psi_s \) — Solute potential (MPa)
• \( i \) — Ionization constant (dimensionless)
• \( C \) — Molar concentration (mol/L)
• \( R \) — Gas constant (8.314 × 10^-3 MPa L/mol K)
• \( T \) — Absolute temperature (K)

Explanation: The equation shows that solute potential becomes more negative with increasing solute concentration and temperature.

3. Importance of Solute Potential

Details: Solute potential is crucial in plant physiology for understanding water movement, osmosis, and turgor pressure. It helps explain how plants absorb water from soil and maintain cell structure.

4. Using the Calculator

Tips: Enter the ionization constant (1 for non-electrolytes, >1 for salts), concentration in mol/L, and temperature in Kelvin. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical solute potential value for plant cells?
A: Most plant cells have solute potentials between -0.5 to -2.5 MPa, depending on the cell type and environmental conditions.

Q2: How does solute potential differ from water potential?
A: Water potential (Ψ) is the sum of solute potential (Ψ_s) and pressure potential (Ψ_p). Solute potential is only one component.

Q3: What is the ionization constant (i) for common solutes?
A: For sucrose (non-electrolyte) i=1, for NaCl (fully dissociated) i≈2, for CaCl₂ i≈3.

Q4: Why is solute potential always negative or zero?
A: Solutes reduce the free energy of water, making the potential lower than pure water (which has Ψ_s=0).

Q5: How does temperature affect solute potential?
A: Higher temperatures make the solute potential more negative because thermal energy increases molecular activity.