Preparing the Dilution Series:

• Using a marker pen label 6 boiling tubes as follows:

  0.0,  0.2,  0.4, 0.6 ,0.8, 1.0.

• Place in a test tube rack.

• Use the provided 1.0M Sucrose solution make 20dm³ of each of the above concentrations of Sucrose solution.

• Stand the test tubes in water bath set to 30°C, using the thermometer make sure all the solutions in the test tubes have reached 30°C.

• Using the cork borer and white tile prepare 6 tubers from the potato. Using the ruler, scalpel and white tile cut each tuber to the same length.

• Roll the tubers, carefully in a piece of paper towel until there is no more liquid blotting on to the paper towel, DO NOT SQUASH THE TUBERS.

• Place each of the tubers onto a clean, dry piece of paper towel, that is labelled the same as your test tubes.

• Weigh each of the tubers, and record the weight in a suitable table.

• Place the tuber into the correctly labelled test tube, and start the stopwatch

• After 20 mins, blot the tubers dry, carefully as you did before

• Reweigh the tubers and record the final mass in your table

• Calculate the change in mass, note some of the values may be a negative number.

• Change in mass = Final mass – Initial mass

• Calculate the percentage change:

  Percentage Change = Change in mass ÷ Initial Mass

• Plot a graph and identify the concentration of sucrose that has the same water potential as the potato tuber.