Diffusion and osmosis experiment

• What is phenolphthalein used for in experiments?

  It is a pH indicator.
• What color does phenolphthalein turn in alkaline solutions?

  Pink
• What color does phenolphthalein turn in acidic solutions?

  Colorless
• How can you investigate diffusion using agar jelly?

  By using phenolphthalein and hydrochloric acid.
• What happens to agar jelly cubes when placed in hydrochloric acid?

  They turn colorless as acid diffuses in.
• What does the rate of diffusion depend on in the agar jelly experiment?

  The size of the cubes and their surface area.
• What is the purpose of cutting potato into cylinders for osmosis experiments?

  To measure changes in length due to osmosis.
• What should be kept constant in the potato osmosis experiment?

  The volume of solution and time.
• What indicates that potato cylinders have drawn in water by osmosis?

  They will be longer after the experiment.
• What is the role of Visking tubing in osmosis experiments?

  It acts as a partially permeable membrane.
• What happens to the sugar solution in the thistle funnel overnight?

  Water is drawn through the tubing, raising the solution.
• What type of solutions are used in the potato osmosis experiment?

  Different sugar solutions, including pure water.
• What are the steps to investigate diffusion in agar jelly?

  1. Prepare agar jelly with phenolphthalein and sodium hydroxide.
  2. Cut cubes and place them in hydrochloric acid.
  3. Observe color change over time.
  4. Measure time for different cube sizes.
• What are the steps to investigate osmosis using potato cylinders?

  1. Cut potato into identical cylinders.
  2. Place in beakers with varying sugar solutions.
  3. Measure initial lengths.
  4. Leave for half an hour and measure again.
  5. Analyze changes in length.
• What are the key components of the Visking tubing osmosis experiment?

  • Visking tubing as a semi-permeable membrane
  • Sugar solution in thistle funnel
  • Beaker of pure water
  • Measure solution height in the tube after overnight