Course 7th Grade Integrated Science
Standard: I Objective 3,c,d
Title: Gobstoppers and Diffusion
Description: Gobstoppers in hot and cold water. Predict what will happen and conduct the experiment.
Materials Needed: 400 ml beakers (smaller beakers and water amounts can be used)
4 gobstopppers
Cold and Hot water
Stop watches
Ice
Time Needed: 45 minutes
Safety issues or specialized background knowledge: If you use a hot plate for the hot water you will need to take precautions. Hot water from the tap works well.
Teacher Procedures:
1. Take a large jaw breaker and start licking it in front of the class. Ask the class if there is a different way to dissolve the jaw breaker.
2. Set up a bin with ice water.
3. Have a source for hot water.
4. Students will run the lab.
5. Discuss after the results.
Scoring Rubric or answer key:
1. Complete, best effort, analysis questions accurately answered..……………4
2. Complete, best effort ……..……………………………………………………...3
3. Partially complete and lacking effort……………………………………………..2
4. Started lab and did not complete…………………………………………………1
Student Page
Standard I Name ______
Objective 3. c, d Date ______
Period ______
Title: Gobstoppers and Diffusion
Introduction: Diffusion can be observed when substances dissolve in water, especially if they are brightly colored, like gobstoppers. If you put gobstoppers into hot and cold water do you think diffusion will happen at the same rate?
Materials Needed:
400 ml beakers (smaller beakers and water amounts can be used)
4 gobstopppers
Cold and Hot water
Stop watches
Ice
Time Needed: 45 minutes
Prediction/Hypothesis
If a gobstopper is put into Hot water then ______.
If a gobstopper is put into Cold water then ______.
Procedures:
1. Put 200 ml of cold water in one beaker and 200 ml of hot water in the second beaker.
2. Let them sit on your table for one minute so that the water is not moving.
3. Drop two Gobstoppers in each of the beakers. Write down or sketch what you see every 2 minutes for 20 minutes for both beakers.
4. Answer the questions.
Data
2 / 4 / 6 / 8 / 1012 / 14 / 16 / 18 / 20
Analysis
1. What is the state of matter of the water?
2. What is the state of matter of the gobstopper?
3. Why are the gobstoppers dissolving? Use the word “diffusion” in your answer.
4. In which beaker did the gobstopper dissolve fastest?
5. Why?
6. How could you make it dissolve even faster?
7. What did you observe about the density of the gobstopper coloring and the water?
8. Give an example of diffusion in your everyday life.
Conclusion: Write down 2 things that you learned.