If your child liked the Exploding Sandwich Bag Science Experiment or tried the Antacid Rocket Experiment, she’s really going to like Bottle Balloon Blow-Up experiments, although she might be a little disappointed when she finds out the only thing getting blown up is the balloon.
Once she realizes that none of the various forces used to blow up the balloons in these experiments require her to use air from her lungs, she’ll be intrigued.
Note: This experiment work best with latex balloons, but if any of your participants have using a different balloon will suffice.
What Your Child Will Learn (or Practice)
The power of carbon dioxide gas
The power of air pressure
An empty water bottle
A medium or large balloon
Create a Hypothesis
This particular version of the experiment shows how the chemical reaction created by combining baking soda and vinegar is powerful enough to blow up a balloon. Talk with your child to see if she can predict what will happen when you combine baking soda and vinegar.
If she’s ever seen a science-fair volcano, remind her that these are the ingredients used in the volcano. Ask her to predict what will happen if you combine these ingredients when instead of leaving a hole in the top you cover the bottle with a balloon.
The Baking Soda Balloon Blow-Up Experiment
Fill a water bottle one-third full of vinegar.
Put a funnel in the neck of a balloon, and hold onto the balloon neck and funnel. Have your child pours in enough baking soda to fill the balloon halfway.
Slide the funnel out of the balloon and have your child hold the portion of the balloon with the baking soda in it down and to the side. Stretch the neck of the balloon over the neck of the water bottle securely. Be careful not to let any of the baking soda fall into the bottle!
Ask your child to slowly hold the balloon over the water bottle to let the baking soda pour inside.
Continue to hold tight to the neck of the balloon, but move to the side listen and watch the bottle carefully. You should hear fizzing and crackling noises as the baking soda and vinegar solution activates. The balloon should begin to inflate.
What’s Going On:
When baking soda and vinegar are combined, the acetic acid in the vinegar breaks down the baking soda (calcium carbonate) into the basics of its chemical composition. The carbon combines with the oxygen in the bottle to create carbon dioxide gas. The gas rises, can’t escape from the bottle and goes into the balloon to blow it up.
Extend the Learning:
Experiment with different size bottles (half-size water bottles, liter bottles, or two-liter soda bottles, etc.) and balloons to see if the amount of oxygen in the bottle makes a difference in how fully the balloon expands. Does the size or weight of the balloon make a difference, too?
Try varying the sizes of balloons and bottles and doing the experiment side by side with the variables changed. Which balloon blows up fuller? Which balloon fills up faster? What was the influencing factor?
Use more vinegar or baking soda and see what happens. As a last experiment, you can also let go of the balloon when the baking soda drops into the vinegar. What happens? Does the balloon still blow up? Does it shoot across the room?
More Baking Soda and/or Vinegar Experiments:
Do a Vinegar & Baking Soda Foam Fight