Osmosis

• What is the aim of the osmosis experiment?

  To investigate water movement in plant tissue
• What equipment is needed for the osmosis experiment?

  • Plant tissue (e.g., potato)
  • Cork borer
  • Ruler
  • Measuring cylinder
  • Labels
  • Boiling tubes
  • Test tube rack
  • Paper towels
  • Sharp knife
  • White tile
  • Salt or sugar solutions
  • Distilled water
  • Top-pan balance
• How long should the potato cylinders be left in the boiling tubes?

  At least 15 minutes
• What is the first step in the method of the osmosis experiment?

  Use a cork borer to cut potato cylinders
• Why should the potato cylinders be trimmed to the same length?

  To ensure consistent surface area for osmosis
• What should be done after measuring the mass of each potato cylinder?

  Measure 10 cm​3​ of sugar solution
• What is the purpose of adding one potato cylinder to each boiling tube?

  To observe the effect of different solutions
• What should be done after removing the potato cylinders from the boiling tubes?

  Blot them dry with paper towels
• How is the percentage change in mass calculated?

  Percentage change = (change in mass / initial mass) * 100
• What is the significance of plotting a graph of change in mass against concentration?

  To find the isotonic concentration for potato cells
• What are the controlled variables in the osmosis experiment?

  • Temperature
  • Amount of drying
  • Type of potato
  • Age of potato
• What is a potential source of error in the experiment?

  Different water potentials in potato discs
• What safety precautions should be taken during the experiment?

  Handle cork borer and knife carefully