Osmosis

•Movement of fluid from and area of lower solute concentration to an area of higher solute concentration

•Some substances form semipermeable membranes, allowing some smaller particles to pass through, but blocking other larger particles.

•In biological systems, most semipermeable membranes allow water to pass through, but solutes are not free to do so.

  In osmosis, there is net movement of solvent from the area of higher solvent concentration (lower solute concentration) to the are of lower solvent concentration (higher solute concentration).

•Osmosis is the spontaneous movement of water across a semi-permeable membrane from an area of low solute concentration to an area of high solute concentration

•Osmotic Pressure - The Pressure that must be applied to stop osmosis

p = i CRT

where p = osmotic pressure

           i = van’t Hoff factor

           C = molarity

           R = ideal gas constant

           T = Kelvin temperature