Soft drink manufacturers add the fizz to their drinks by adding carbon dioxide (CO2) to the mix. CO2 is dissolved into the drink. When you open a can of a carbonated beverage, the pressure is released and the CO2 comes out of solution. The CO2, then, forms bubbles that rise to the top of the drink and attach to the sides of the container the beverage is in.
If you look closely at a glass filled with a carbonated beverage, you can see that the bubbles initially form on the surface of the glass. Some remain there and others rise to the top and release the CO2 gas into the air. When the CO2 comes out of solution it always happens at a physical reaction point, such as the side of the glass.
Let's experiment with this phenomena and see if we can change the reaction in some way.
Bubbles Experiment
Supplies
- small jar or beaker
- clear carbonated beverage/soda
- food coloring
- table salt
Procedure
- Fill the jar 3/4 full of soda
- Add a drop of food coloring just for fun
- Add 1 tablespoon of salt
What Happened
As we discussed before, CO2 is added to carbonated beverages to give them their fizzy bubbles. These bubbles form on reaction points, such as the sides of a drinking glass, when the pressure of the original container is released.
When the salt was added to the soda, more reaction points were added to the mix. CO2 came out of the solution on the sides of the salt crystals and formed bubbles. The mass of bubbles caused a foaming action.
Take this bubbles experiment further by adding different amounts of salt or adding a type of salt with larger crystals. Note the changes in the amount of bubbles that form.
Why Add Food Coloring?
The food coloring did not affect the reaction in this experiment. The addition of color can sometimes help to see the reaction easier. Also, you can use this bubbles experiment to learn about color mixing. Create two reactions side-by-side using two different colors, such as blue and yellow. As the foaming bubbles mix, note the colors that form.
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Marci is a Christian wife, homeschool mom, science geek, softball coach, hockey mom and blogger, who needs her morning coffee, hair done and make-up on before attempting of those things. You can find her blogging at The Homeschool Scientist
