This activity is designed for the Grade 9 Science, Mathematics, and Technology Program. Specifically, it fits into Core Unit 2, Chemical Change, of the former Advanced Level Science course, and should be used during the work on separation of substances.

This activity will reinforce earlier concepts on classification of substances. It should be performed after the topic of density has been covered. It may be used after a more traditional activity on separation of a mixture (sand, salt, calcium carbonate, iron filings, water). This activity could be presented as a problem in which the students must write a method or in which they test various ideas which they have. At any time during a grade 9 or 10 course if oil spills are a current topic, this activity could be performed in conjunction with some current newspaper articles or news footage. It would be a one period break from the regular schedule.

This activity can also be used in the Grade 10 level science course, during the unit on "Environmental Chemistry," subtopic "Water Pollution." Separation of substances should have been covered in Grade 9. This activity could be used as an example of water pollution. Possible extensions could include a discussion of our dependence on oil (Wise Use of Resources), the effects of oil spills on wildlife, and clean up procedures.

Learning Outcomes

• Teaching, learning and evaluation will focus on the student's ability to:
• Recognize and classify mixtures as homogenous and heterogeneous;
• Describe the properties of an oil and water mixture;
• Identify methods of separating mixtures;
• Design and perform experiments to separate an oil water mixture;
• Evaluate the success of an experiment;
• Predict the success of a classroom experiment on a larger scale;
• Appreciate the difficulty and frustration involved in cleaning up oil spills;
• Consider our dependence on oil and evaluate the consequences of this.

Classroom Development

1. This messy activity should be performed with students who are comfortable with laboratory routines.
2. The students will consider the properties of the oil and water mixture and devise methods of separation. They should be provided with materials. Separation methods may include filtration, absorption by cotton wool or paper towel, skimming and the addition of detergent. Students will consider three different methods. Analysis of this problem will show them that there is often more than one way to a solution.
3. This activity can run over 2 periods. In the first, students examine and classify the oil and water mixture. For homework, they can devise ways to separate this mixture. The following period they can perform the experiment.
4. Depending on current events, this topic may warrant more time.
5. Vertical files in the library are a source of current articles on this topic.

Cross-disciplinary Links

Links with the Self and Society program can be established. If you are concentrating on a particular spill, the geographic location and physical geography of the coast should be considered. Other considerations may include: the economic significance of a spill, the corporate responsibility or lack thereof, and worldwide dependence on oil. Students could write to an oil company, inquiring about its methods for cleaning up oil spills, and copies of any risk-benefit analysis which the company has done.

Student Activities

Clean-Up Crew

Purpose

To simulate an oil spill on the ocean and evaluate methods of clean-up.

Materials

pie plate or plastic tray funnel

filter paper detergent

test tube and stopper thread

water sawdust

oil screen or sieve

salt cotton wool

spoon or scoop feathers

Method

1. Half fill a test tube with water; add one quarter of a test tube of oil. Describe this mixture.
2. Stopper and shake this mixture. Then allow it to settle. Describe the result.
3. Repeat this procedure with half a test tube of water and a small scoop of salt.
4. Fill the pie plate with water. Add several scoops of oil to form a slick covering the surface of the water.
5. Dip a feather and your finger into the oil. Describe what happens to the feather. How does your finger feel?
6. Think about separating the oil from the water using the materials which are available to you. Write out a step by step method, then perform the experiment.
7. Record observations.
   

Observations

1. Oil and water mixture
2. Salt and water mixture
3. Methods of separation

Method	How Well Did it work?	Problems Encountered

Questions

1. Mixtures may be classified as homogeneous or heterogeneous. How would you classify the oil and water mixture; the salt and water mixture?
2. Does the oil dissolve in the water? Explain your answer.
3. What can you conclude about the density of the oil compared to the density of water?
4. What was the effect of the oil on the feather? What effect would oil have on birds which come in contact with oil?
5. Comment on the success which you had separating the oil from the water. Do you think that any of these methods would work on a larger scale?
6. Are there any disadvantages to the large scale use of the methods which you have used? If so, what are they?

Extensions

Research a major oil spill, the clean-up procedures used and the effect of the oil spill on wildlife and the rest of the environment.