Osmosis

• Osmosis is the movement of water molecules from a region of higher water concentration to a region of lower water concentration
• Water can pass both ways through a partially permeable membrane during osmosis because of the molecules random movement. This said, the net flow is into the region with fewer water molecules.
• Observing effect of sugar solutions on plant tissue

  1. Use a ruler to measure and cut a potato into 6 5cm cylinders. Measure their mass.
  2. Fill 6 beakers - one with pure water and the rest with increasing concentrations of sugar solution (0.2 mol/dm3, 0.4 mol/dm3, 0.6 mol/dm3, 0.8 mol/dm3 and 1 mol/dm3)
  3. Leave each cylinder in each beaker for 24 hours
  4. Take the cylinders out, dry with a paper towel and measure their masses again
  5. If they have increased in mass they have absorbed water through osmosis