CSEC Integrated Science Paper 3 May/June 2011 - Free CXC Past Paper with Answers

Examine the diagrams of the potato strips at the beginning of the experiment as shown in Figure 2a. Measure the length of the strips and record your measurements in Table 2.

Examine the diagrams of the potato strips at the end of the experiment as shown in Figure 2b. Measure the length of the strips and record your measurements in Table 2.

Calculate the change in length for EACH strip and write your answers in Table 2.

TABLE 2:

Which potato strip had the GREATEST increase in length?

Suggest a reason why the length of all the potato strips did NOT increase by the same amount.

What is the name of the process that is responsible for the change in length of the potato strips?

Suggest a suitable title for your table in the space provided at the top of the table.

State ONE variable that was controlled in the experiment.

Why were four strips of potato used in the experiment?

How can the experiment be modified to investigate the effect of a solute on the direction of movement of a solvent?

Identify ONE variable that would be controlled in the experiment in (e) (i) above.

Write a hypothesis for the modified experiment.

Draw and label a large diagram of ONE of the measuring cylinders and its contents used in the experiment.

Why was it more appropriate to use measuring cylinders than boiling tubes in the experiment?

What THREE precautions should John take when using the measuring cylinders to ensure the most accurate results?

Why did John wash the measuring cylinders before performing the experiment?

State an appropriate aim for the experiment that John performed.

List ALL the apparatus and materials that John used to perform this experiment.

Record the results of the experiment in Table 3 below.

TABLE 3

Write a suitable title for Table 3 above.

From the results that John obtained indicate which of the samples of water, A, B, C, or D, was the HARDEST.

Give a scientific explanation for your answer in (d) (i) above.