LAB: Bubbles! Name __________________________________

Date _____________________ Period________

PURPOSE

To test the hypothesis that bubble making can be affected by adding sugar or salt to a bubble-blowing mixture.

MATERIALS

• 3 plastic drinking cups • liquid dish detergent • spoons • • water

• graduated cylinder • table salt • drinking straw • table sugar

PROCEDURE

1. Using masking tape, label three drinking cups 1, 2, and 3. Measure and add one spoon of liquid dish detergent to each cup. Use the graduated cylinder to add 150 mL of water to each drinking cup. Then swirl the cups to form a clear mixture.

CAUTION: Wipe up any spills immediately so that no one will slip and fall.

2. Add a spoon of table sugar to cup 2 and add a spoon of table salt to cup 3. Swirl each cup for one minute.

3. Dip the drinking straw into cup 1, remove it, and blow gently into the straw to make the largest bubble you can. Practice making bubbles until you feel you have reasonable control over your bubble production.

4. Repeat Step 3 with the mixtures in cups 2 and 3.

DATA AND OBSERVATIONS:

Describe the bubbles produced from each of the cups.

ANALYSIS AND CONCLUSION:

1. What, if any, differences did you observe in your ability to produce bubbles using the mixtures in cup 1 and cup 2?

2. What, if any, differences did you observe in your ability to produce bubbles using the mixtures in cup 1 and cup 3?

3. What can you conclude about the effects of table sugar and table salt on your ability to produce bubbles?

4. What is the independent variable in this experiment?

5. What is the dependent variable in this experiment?

6. a) Since all matter is made up of atoms and molecules, how do the atoms and molecules of the mixture have to behave to produce bubbles?

b) What affect does sugar have on this behavior?

c) What affect does salt have on this behavior?

7. Propose another hypothesis related to bubble making, and design an experiment to test your hypothesis.