Craft-Turned-Toy: Self-Inflating Forky
How we did it:
- glass bottle
- citric acid (1 tablespoon)
- baking soda (1 tablespoon)
- water (1/4 cup)
- white balloon
- red pipe cleaners (3)
- lightweight, air-dry clay (red and blue)
- glue stick
- black permanent marker
- scissors (optional)
- sticky foam (optional)
Using the funnel, add one tablespoon of citric acid and one tablespoon of baking soda to the glass bottle.
Step 2Lightly swirl the bottle to mix the two powders together.Place the balloon next to the bottle so it’s close by when you need it. (It should be ready to stretch over the bottle’s mouth as soon as the water is poured in the next step, so you can capture the gas before it goes to infinity and beyond!)
Pour ¼ cup of water through the funnel into the bottle. The mixture will bubble and react, releasing carbon dioxide gas. With your balloon ready, quickly jump to Step 4.
Step 4Once the water is poured in, stretch the balloon’s opening over the top of the bottle. You want it centered and down far enough on the bottle that it won’t come off. The balloon will start to inflate from the gas and continue to grow over the next one to two minutes.
If the carbon dioxide gas escapes from the bottle before the balloon is stretched over its mouth, you may have to try again. The reaction works best with a clean and dry bottle, so before you start again, rise the bottle and let it dry. Then repeat Steps 1-3.
To make Forky’s arms, wrap a red pipe cleaner around the middle of the bottle so the two ends stick out. Shape the remaining two pipe cleaners into Forky’s hands. Attach the hands to each end of Forky’s arms.
Shape the red clay into Forky’s eyebrows and the blue clay into his mouth. You can also use scissors to cut out these shapes from sticky foam. Apply the googly eyes and clay or sticky foam eyebrows and mouth to the balloon. If needed, use a glue stick to attach them. To create the outline of Forky’s head, use a black permanent marker to draw a spork shape around his features. Welcome to the world, Forky!
How does this work? Acids (like citric acid) and bases (like baking soda) do something special when they’re combined in water. In water, their molecules (the smallest piece of a substance) are free to float around and react with each other. This chemical reaction creates something completely new: carbon dioxide gas! That’s what will bubble up and create all the foamy fizz in your bottle. And once you stretch the balloon over the bottle’s mouth, you create an airtight seal. Then the gas flows up into the balloon, causing the balloon to inflate!