Building Up the Fizz in Soda

Research Questions:

• How does dropping an ice cube into soda affect the carbonation?
• How does the size of an ice cube dropped into a glass of soda affect the fizz time?

Drop an ice cube into a glass of soda, and you’ll see fizz rise to the surface. But does the size of the ice cube affect the amount of fizz that forms? Find out with this simple experiment that uses homemade ice cubes of different sizes.

Materials:

• 15 ice cubes
• 5 small plates
• Freezer
• Cup
• Bottle of soda
• Stopwatch or watch with a second hand

Experimental Procedure:

1. Rinse five ice cubes in cold water for just a second or two.
2. Cluster them together on a plate so that they are all touching, and place the plate in the freezer. They will freeze into a clump.
3. Do the same thing with a group of four, three, and two ice cubes. Set a single ice cube aside on a fifth plate.
4. Fill the glass three-quarters full with soda. Screw the top back on the soda tightly when finished.
5. Wait until the fizz on the top of the soda has died down.
6. Drop one of the ice cubes into the cup and time how long it takes for the fizz to die down. Make sure to drop it from the same level as the surface of the glass.
7. Record your data.
8. Pour out the soda (or, better yet, drink it!), and rinse the cup well. 9. Repeat this process with each of the rest of the ice cubes, using a new glass of soda each time.
9. Analyze your data by creating a line graph that shows the relationship between fizz time and the size of the ice cube dropped in.

Terms/Concepts: Carbonation; What causes fizz to form on top of soda?; How does pressure release carbonation?

References:

First Place Science Fair Projects for Inquisitive Kids, by Elizabeth Snoke Harris. Page 92.