💧 Water Potential Calculator
Estimate a solution’s solute (osmotic) potential and total water potential using the van’t Hoff equation, useful for plant physiology and cell biology coursework.
What Is Water Potential?
Water potential (Ψ) measures the tendency of water to move from one area to another, driven mainly by solute concentration and physical pressure. Water always moves from a region of higher (less negative) water potential to a region of lower (more negative) water potential, which is why this concept explains osmosis and water movement in plant cells.
How This Calculator Works
The solute (osmotic) potential is calculated with the van’t Hoff equation: Ψs = -iCRT, where i is the ionization constant of the solute, C is molar concentration, R is the pressure constant (0.008314 L·MPa/mol·K), and T is temperature in Kelvin. The total water potential then adds the pressure potential (Ψp) you supply, representing physical pressure such as turgor pressure in a plant cell: Ψ = Ψs + Ψp.
Interpreting Your Result
A more negative total water potential means the solution pulls water toward it more strongly. Comparing two water potentials tells you which way water will flow between them until equilibrium is reached. This tool is provided for general biology education and planning purposes and does not account for matric potential, which can matter in soils or cell walls.