**3.1 - 2016 June Q3**

(a) A student carries out an investigation into the effect of different concentrations of sugar solution on the mass of potato cylinders.

This is the method the student uses.

The results are given as a percentage change in mass of the potato cylinders. The concentration of sugar is given in arbitrary units (au).

The student’s results

This is the method the student uses.

- wrap each potato cylinder in filter paper
- remove each potato cylinder from the filter paper and weigh
- place each potato cylinder into a sugar solution of known concentration
- remove the potato cylinders after two hours
- wrap the potato cylinders in filter paper, then remove from the filter paper and reweigh

The results are given as a percentage change in mass of the potato cylinders. The concentration of sugar is given in arbitrary units (au).

The student’s results

(i) Draw a table with column headings to display the student's results. (4)

(ii) Plot a graph of the results. Draw a line of best fit. (4)

(ii) Plot a graph of the results. Draw a line of best fit. (4)

(iii) Use your graph to find the concentration of sugar that would produce no change in the mass of the potato cylinders. (1)

concentration of sugar = .................................................................... au

(b) (i) State the process that causes the change in mass of the potato cylinders. (1)

(ii) Explain how this process causes the change in mass of the potato cylinders. (2)

(iii) Suggest why the potato cylinders are wrapped in filter paper at the start and at the end of the investigation. (2)

(iv) Each cylinder was left in its solution for two hours. State two other factors that should be kept constant during this investigation. (2)

(ii) Explain how this process causes the change in mass of the potato cylinders. (2)

(iii) Suggest why the potato cylinders are wrapped in filter paper at the start and at the end of the investigation. (2)

(iv) Each cylinder was left in its solution for two hours. State two other factors that should be kept constant during this investigation. (2)

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