OSMOSIS
(Equipment no longer available.)

EQUIPMENT
    1000 ml Beaker
    Dilute Sugar Mixture
    Osmosis Vessel
  


NARRATIVE
               Osmosis is the process of preferential diffusion through a semipermeable membrane. The membrane (a porcelain vessel) used in this demonstration will allow pure water to pass through but prohibits the flow of a more dense sugar solution.

            Fill a 1000 ml beaker about ½ full of water. Mix a dilute sugar-water solution and pour in into the osmosis vessel. Immerse the osmosis into clear water. Sugar molecules prevent the water molecules in the vessel from leaving through the semipermeable membrane, but they do not prevent water molecules surrounding the vessel from entering.

            Consequently, the pressure in the vessel is higher than in the beaker as evidenced by the higher level in the vessel tube.