How to calculate osmotic pressure

Osmosis is the diffusion of a fluid through a semipermeable membrane. When a semipermeable membrane (animal bladders, skins of fruits and vegetables) separates a solution from a solvent, then only solvent molecules are able to pass through the membrane. The osmotic pressure of a solution is the pressure difference needed to stop the flow of solvent across a semipermeable membrane. The osmotic pressure of a solution is proportional to the molar concentration of the solute particles in solution.

?=inRTV=iMRT

where

? is the osmotic pressure,
R is the ideal gas constant (0.0821 L atm / mol K),
T is the temperature in Kelvin,
i is the number of ions,
n is the number of moles of solute present,
V is the volume of the solution ( nV is then the molar concentration of the solute), and
M is the molar mass of the solute.