Activity Title: Create Your Own Fizzy Drink
What Do I Need?
- Leather gloves
- Apple juice — for best results, make sure juice is very cold
- Glass cups
- Dry Ice (find local distributors at www.dryicedirectory.com)
Note: Before purchasing or handling dry ice, review and follow dry ice safety guidelines.
How Do I Do It?
- Start by having your pre-teen make some observations on carbon dioxide. Where is carbon dioxide found and how is it produced? What are the effects of too much carbon dioxide in our atmosphere? Why do scientists try to find ways to store away carbon dioxide?
- Pour cold apple juice into a glass cup – Make a note of how the apple juice tastes and the color. Predict what will happen if dry ice is added to the juice.
- Using leather gloves, drop a small piece of the dry ice into the cup of juice. Use a straw to stir the juice continuously. Make a note of the effect the dry ice has on the juice.
- Once the dry ice has fully vaporized and no more bubbling can be seen, compare the taste and appearance of the juice. How have the taste and appearance of the juice changed?
- Leave the cup of juice on a counter overnight and observe the juice in the morning. How have its appearance and taste changed when left exposed overnight? What might happen if the cup were tightly sealed and left overnight? Can your daughter explain why liquid carbonation is or is not a good method for carbon sequestration.
What's the Science Behind It?
Dry ice is frozen carbon dioxide. Since dry ice is a frozen type of gas, it does not melt into a liquid. Instead, it undergoes a process called sublimation. Sublimation occurs when a substance changes directly from the solid phase to the gas phase — as chemists say, when a substance sublimes. When dry ice is placed inside a cup of juice, the heat from the juice transfers to the dry ice and causes it to sublime even faster, releasing carbon dioxide gas into the liquid.
Since carbon dioxide is somewhat soluble in liquids, a small amount of the gas will dissolve into the juice. This dissolved carbon dioxide makes the liquid slightly acidic, giving it a tart taste. The dissolved carbon dioxide also makes the juice fizzy or carbonated, as evidenced by the random formation of small bubbles throughout the juice. These are bubbles of carbon dioxide that have formed at nucleation sites, or locations where dissolved carbon dioxide molecules have come together to form a gas again.
If left exposed to the air, the carbon dioxide eventually will exit the liquid in a gaseous form, in the same way that soda will eventually go “flat.” Liquid carbonation is not the best method to use for carbon sequestration, since the resulting effect is carbon dioxide being released back into the atmosphere.