Diffusion

• What is the title of the experiment described?

  Diffusion
• What apparatus is used in the diffusion experiment?

  • 3 x 10 cm³ of hydrochloric acid (0.1, 0.5, 1.5, 2 mol)
  • Phenolphthalein indicator
  • Clamp stand
  • Boiling tube
  • White tile/sheet of paper
  • Stopwatch/clock
• What is the purpose of phenolphthalein in the experiment?

  It indicates the pH change in the solution
• How much hydrochloric acid solution is poured into the boiling tube?

  10 cm³
• What should be done immediately after placing the agar cylinder in the boiling tube?

  Start the timer
• What is measured to determine the reaction time in the diffusion experiment?

  Time for pink color to disappear
• How many times should the steps be repeated for accuracy?

  Three times
• What apparatus is used in the temperature and pH experiment?

  • 2 ml of pH 3-8 buffer solutions
  • 6 x 3 ml pepsin
  • 6 x 10 ml egg white
  • 6 x test tubes
  • Test tube rack
  • Measuring cylinder
  • 37°C water bath
  • Stopwatch/clock
• What is the first step in the temperature and pH experiment?

  Label six test tubes 1-6
• How much egg white suspension is added to each test tube?

  10 ml
• What is added to the test tubes after the egg white suspension?

  2 ml of pH buffer solution
• What temperature should the water bath be set to?

  37°C
• What is done after placing the test tubes in the water bath?

  Leave for 5 minutes
• What is added to the first test tube after the incubation period?

  3 ml of pepsin
• What is recorded after adding pepsin to the test tube?

  Time taken for egg white to change color
• How many times should the steps be repeated for the temperature and pH experiment?

  Three times