Water flux, equilibrium height, and the Van't Hoff law Π = iMRT
A semipermeable membrane allows water (solvent) to pass but blocks solute. Water flows from low to high solute concentration until osmotic pressure is balanced by hydrostatic head.
Π: osmotic pressure (Pa)
i: van't Hoff factor (dissociation)
M: molar concentration (mol/L)
R = 8.314 J/mol·K
T: temperature (K)
At equilibrium: Π = ρgh where h is the height difference.