Osmosis practical

• What is the volume of sucrose solutions used in the test tubes?

  10 cm³
• What is the range of sucrose concentrations used in the experiment?

  From pure water to 1 mol/dm³
• How should the potato be prepared for the experiment?

  Cut into equal-sized cylinders
• What should be done with the potato cylinders before placing them in the solutions?

  Measure and record their masses
• How long should the potato cylinders be left in the sucrose solutions?

  24 hours
• What should be done after removing the potato cylinders from the solutions?

  Dry them with a paper towel
• Why might you repeat the experiment with different potato cylinders?

  To identify anomalous results
• What is the independent variable in this experiment?

  The concentration of sucrose solutions
• What are the control variables in this experiment?

  Volume, time, temperature, type of sugar
• What does an increase in potato mass indicate?

  Water moved into the potato cells
• What does a decrease in potato mass indicate?

  Water moved out of the potato cells
• How can you calculate the rate of water uptake/loss for each potato cylinder?

  Using the change in mass over 24 hours
• What is the formula for calculating the rate of change?

  Rate = change in mass / 24 hours
• How do you calculate the percentage change in mass?

  Using final mass minus original mass
• What does a positive percentage change in mass indicate?

  The mass of the potato increased
• What does a negative percentage change in mass indicate?

  The mass of the potato decreased
• How can you display the results of the experiment?

  Plot percentage change against sucrose concentration
• What does the concentration of sucrose inside the potato indicate?

  Where the line of best fit crosses the x-axis
• What is the concentration of sucrose inside the potato if there is no net movement of water?

  0.3 mol/dm³
• What is the volume of sucrose solutions used in the test tubes?

  10 cm³
• What is the range of sucrose concentrations used in the experiment?

  From pure water to 1 mol/dm³
• How should the potato be prepared for the experiment?

  Cut into cylinders of equal size
• What should be done after placing the potato cylinders in the solutions?

  Leave them for 24 hours
• What should you do after removing the potato cylinders from the solutions?

  Dry them and measure their masses
• Why might you repeat the experiment with different potato cylinders?

  To identify anomalous results
• What is the independent variable in this experiment?

  The concentration of sucrose solutions
• What are the control variables in this experiment?

  Volume, time, temperature, type of sugar
• What does an increase in potato mass indicate?

  Water moved into the potato cells
• What does a decrease in potato mass indicate?

  Water moved out of the potato cells
• How can you calculate the rate of water uptake/loss for each potato cylinder?

  Using the change in mass over 24 hours
• What is the formula for calculating the rate of change?

  Rate = change in mass / 24 (hr)
• How do you calculate the percentage change in mass?

  Using final mass minus original mass
• What does a positive percentage change in mass indicate?

  The mass of the potato increased
• What does a negative percentage change in mass indicate?

  The mass of the potato decreased
• How can you display the results of the experiment?

  Plot percentage change against sucrose concentration
• What does the concentration of sucrose inside the potato indicate?

  Where the line of best fit crosses the x-axis
• What is the concentration of sucrose inside the potato if there is no net movement of water?

  0.3 mol/dm³