Osmosis practical

• What is the purpose of the potato borer in the experiment?

  To remove a cylinder of potato
• Why must the potato cylinders be the same length?

  To ensure a control variable
• What must be controlled regarding the potato species?

  Use the same species of potato
• What are the control variables in this experiment?

  Species, age, surface area, and volume
• How long should the potato cylinders stay in the sugar solutions?

  30 minutes
• Why is it important to dab the potato cylinders on tissue paper?

  To remove excess water affecting results
• What should be recorded for each potato cylinder?

  Initial and final mass
• What is the equation for calculating percentage change in mass?

  Percentage change = (final mass - initial mass) / initial mass × 100
• If the initial mass is $5.8 \text{ g}$ and the final mass is $6.5 \text{ g}$, what is the percentage change?


  $12.07\%$
• What does a straight inversely proportional line on the graph indicate?

  Relationship between percentage change and sugar concentration
• What does the intersection of the line with the x-axis represent?

  The concentration of sugar inside the potato
• What is the approximate sugar concentration inside the potato?

  Just below 0.6 moles
• What are the steps to prepare the potato cylinders for the experiment?

  • Use a potato borer to extract cylinders
  • Cut cylinders to the same length with a scalpel
  • Measure initial mass of each cylinder
  • Place in sugar solutions for 30 minutes
  • Dab with tissue to remove excess water
  • Weigh to find final mass
• What factors must be controlled during the experiment?

  • Volume of sucrose solution
  • Temperature of the beakers
  • Time in sugar solutions
• How do you calculate the percentage change in mass for the potatoes?

  1. Subtract initial mass from final mass
  2. Divide by initial mass
  3. Multiply by 100