osmosis

• Osmosis

  Diffusion of water through a selectively permeable membrane
• Osmosis factors affecting rate

  Factors affecting rate - surface area, water potential gradient, thickness of exchange surface
• Osmosis practical

  - Cut up a potato into identical cylinders

  - Get some beakers with different sugar solutions in them, one should be pure water and another should be a very concentrated sugar solution and some in between.

  - Measure the mass of the cylinders and leave each one in each beaker for a day

  - Take them out, dry them and weigh them again

  - If water has been drawn in by osmosis they will have increased in mass

  - If water has be drawn out they will decrease in mass

  - Dependant variable is the chip mass

  - Independent variable is the concentration