Get set for a wow-worthy balloon Halloween science activity that makes balloons “boo-loon!” Kids watch chemistry come to life with pantry staples (and they’ll want to try this one year after year!).
- Balloon fun A Halloween science activity for kids
- How the Halloween science activity works
- Materials
- How to do the balloon Halloween science activity
- What kids learn in this balloon Halloween science experiment
- Halloween science activity for different ages
- Conversation starters for this Halloween science activity
- Vocabulary kids can learn
- Frequently Asked Questions
Balloon fun: A Halloween science activity for kids
This simple balloon reaction is the kind of kitchen chemistry that kids LOVE.
Kids pour, tip, and watch the balloon grow like it’s powered by Halloween magic…except it’s science!
It’s a two-minute setup with supplies you likely already have, ideal for a preschool Halloween party or a quick home/school activity.
Best of all, it’s repeatable, so little scientists can test, tweak, and try again.
🎃 Related: Check out this spooktacular list of the 50+ best Halloween activities for kids!
How the Halloween science activity works
When baking soda (a base) meets vinegar (an acid), they react to make carbonic acid, which quickly breaks apart into water and carbon dioxide gas.
That gas needs space, so it rushes upward and fills the balloon, and abracadabra: expansion!
Because the bottle opening is narrow, the gas is funneled into the balloon rather than floating away into the room.
👻 There’s more Halloween science where this came from:
- Ooey gooey Halloween oobleck
- Fizzing spiders with baking soda and vinegar
- Easy melting “ghosts” with water, paint, and googly eyes
- Glorious Halloween bubble foam
Materials
Friends Art Lab is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program. As an Amazon Associate, I earn from qualifying purchases. Read more about these links in my disclosure policy.
- Empty plastic water bottle
- White vinegar
- Baking soda
- Balloons
- Black permanent marker
- Funnel – or paper cone
- Food coloring – optional
How to do the balloon Halloween science activity
- Blow up a balloon about half way, and without tying it, draw a Halloween shape. Deflate.
- Fill a water bottle ⅓–½ full with white vinegar. If desired, add a few drops of food coloring for a spooky hue (it’s fun, but completely optional).
- Using a funnel, add a couple of tablespoons of baking soda to an uninflated balloon (no need to measure exactly).
- Stretch the balloon mouth over the bottle opening, keeping the baking soda tucked up in the balloon. Make sure it’s sealed snugly.
- Lift the balloon upright so the baking soda falls into the vinegar. Stand back and watch the fizz!
💡 Teacher Tip: Repeat with small changes (more/less baking soda, warmer/cooler vinegar, different bottle sizes) and compare balloon growth.
What kids learn in this balloon Halloween science experiment
- Cause and effect: Kids see that combining two ingredients creates a visible reaction.
- States of matter: A liquid and a solid create a gas, and that gas takes up space.
- Scientific habits: Predicting, testing, and recording results.
Halloween science activity for different ages
- Younger kids: pre-load balloons and let them focus on the “tip and watch” moment; add simple words like “mix,” “bubble,” and “grow.”
- Preschoolers: invite them to scoop baking soda, funnel it in, and draw prediction pictures before they start.
- Early elementary: introduce variables (amounts, temperatures), timers, and simple data tables.
- Group tip: set this up as a station at a preschool Halloween party so kids rotate through safely and quickly.
Conversation starters for this Halloween science activity
- “What do you notice before we mix the ingredients?”
- “What do you predict will happen to the balloon—witch way will it grow?”
- “How could we make the balloon inflate even more next time?”
- “Where do you think the bubbles are going?”
- “How can we measure the balloon without letting the gas escape?”
Vocabulary kids can learn
- Acid: a liquid that can react with bases (vinegar).
- Base: a substance that reacts with acids (baking soda).
- Reaction: when two things mix and change into something new.
- Gas: matter that spreads out to fill space (carbon dioxide).
- Inflate: fill with air or gas to become bigger.
Frequently Asked Questions
Start with 2ish tablespoons, then experiment with more/less to see how it affects the reaction.
Roll a paper cone or use a clean measuring spoon to pinch-and-pour baking soda into the balloon.
Common reasons: not enough baking soda, cold vinegar, or a leaky seal at the bottle neck.
LEAVE A COMMENT