Paper 1 H - SAMPLE SET 1 Q5
This is the method used.
1. Add 30 cm3 of 0.8 mol dm−3 sugar solution to a boiling tube.
2. Repeat step 1 with equal volumes of 0.6, 0.4 and 0.2 mol dm−3 sugar solutions.
3. Use water to give a concentration of 0.0 mol dm−3.
4. Cut five cylinders of potato of equal size using a cork borer.
5. Weigh each potato cylinder and place one in each tube.
6. Remove the potato cylinders from the solutions after 24 hours.
7. Dry each potato cylinder with a paper towel.
8. Reweigh the potato cylinders.
Table 2 shows the results
Percentage change in mass = _________________ %
5.2) Why did the student calculate the percentage change in mass as well as the change in grams?
[1 mark]
5.3) Complete Figure 3 using data from Table 2.
• Choose a suitable scale and label for the x-axis.
• Plot the percentage (%) change in mass.
• Draw a line of best fit.
[4 marks]
Concentration = ______________________ mol dm−3
5.5) The results in Table 2 show the percentage change in mass of the potato cylinders.
Explain why the percentage change results are positive and negative. [3 marks]
5.6) Suggest two possible sources of error in the method given on page 16. [2 marks]
1 ___________________________________________________
2___________________________________________________
(Total for Question 5 = 13 marks)