Osmosis

• What is the process called that involves the movement of water across a semi-permeable membrane?

  Osmosis
• What are the four steps to investigate the effect of sugar or salt solutions on plant tissue?

  1. Cut a potato into identical cylinders.
  2. Measure the mass of each cylinder.
  3. Prepare beakers with different concentrations of sugar/salt solutions and pure water.
  4. Leave for 24 hours, dry, and measure masses again.
• What is the independent variable in the investigation of sugar or salt solutions on potato cylinders?

  Concentration of sugar or salt solution
• What is the dependent variable in the investigation of sugar or salt solutions on potato cylinders?

  Mass of potato cylinder
• What happens to the mass of a potato cylinder if water is drawn in by osmosis?

  The mass increases
• What happens to the mass of a potato cylinder if water is drawn out by osmosis?

  The mass decreases
• How do you calculate the percentage change in mass of the potato cylinder?

  $\% \text{ change in mass} =$$\frac{\text{new mass} - \text{original mass}}{\text{original mass}} \times 100$
• What should you do with the potato cylinders after leaving them in the solution for 24 hours?

  Dry them gently with a paper towel
• What type of solutions are used in the investigation?

  Sugar or salt solutions and pure water
• Why is it important to cut the potato into identical cylinders?

  To ensure consistent surface area and volume
• What is the significance of measuring the mass before and after the experiment?

  To determine the effect of osmosis