Properties of water

Thinking about learning


The Learning Log

After each lesson complete a learning log at the back of your jotter. A learning log should include at least two of the following headings, especially 5): The headings should start ...
1) I really enjoyed ....
2) I want to find out more about ....
3) I was unsure about ... .
4) I was surprised by ...
5) I learned that ...

For more information on learning logs click for the
The Young Scientist's Handbook .
and see page 4.

Homework 1 Investigating Solubility

Option 1 (i) Write down the meaning of the following four terms: Solvent, Solute and Solution.
(ii) Illustrate your answer with a diagram.

Option 2 We investigated 6 solutes in class to determine if the were soluble in water. Write a report on this activity. Your result should be presented in a table. The evaluation could mention possible improvements to the activity, difficulties you overcame in carrying out the activity and any other related activity you can think of.

Homework 2 Investigating Solutes and solvents

Part 1 (i) Two pupils carried out an investigation on salt and water, the heading of the activity was 'Salt and Volume. The pupils used 5 ml, 10 ml, 15 ml and 20 ml of water. They found. 6, 12, 18 and 24 spatulas of salt of dissolved in each volume. They also found that one spatula weighed 0.5 g. Complete the table below, the second row has been completed for you.
Volume of water (ml) Salt dissolved (Spatulas) Salt dissolved grams (g)
- - -
10 12 6

Part 1 (ii)
i) Present this information as a line graph. Remember the left hand side of the table is plotted on the horizontal axis.
ii) Look at the graph and write down what the pupils found out.



Part 2 (i) Two pupils carried out an investigation on salt and water, the heading of the activity was 'The solubility of salt in water at 20 o C. The pupils used 5 ml, 10 ml, 15 ml and 20 ml of water. They found. 7, 15, 20 and 28 spatulas of salt of dissolved in each volume. They also found that 5 spatulas of Salt had a mass of 2.0 g. If solubility means the amount of solute that dissolves in 1 ml, then complete the following table.
Volume of water (ml) Salt dissolved (g) Solubility (g/ml)

Part 2 (ii)
i) Plot a graph of volume against solubility. Remember the left hand column of the table is plotted on the horizontal axis.
ii) A Pupil says the greater the volume of water we have the greater the amount of salt that will dissolve, this means solubility increases with volume. Do you agree? Explain your answer.

Homework 3 Investigating Solvents

(Do this homework for Friday 10th May if you can. If you are stuck then speak to me on Friday and hand it in on Tuesday 14th..
Mr Rosenberg)

Part A
The diagram below shows glass rods painted with five different paints. To investigate the solubility of each paint, the rods are dipped into the solvent.
Investigating Solvents
(A)
(i) From the above diagram identify the solutes.
(ii) How does the experimenter control the variables? This means what does he or she do to keep the experiment fair; mention two things.
(B)
After removing the rods the test tubes are closely examined. The investigator concludes that the solvent is effective at dissolving the red paint but not quite as effective at dissolving the blue paint. The other paints do not seem to dissolve at all.
(i) What did the investigator observe to make this conclusion?
(ii) Present the investigator's results in a table.
(iii) Mention two things the experimenter could do to that might dissolve the other paints.

Part B
Solvents can be particularly nasty substances. They can give us headaches and many of them catch fire easily. Suppose you were asked to investigate an unfamiliar solvent, what safety measures would you take?