Chemical Reactions & Gas

Fizz-Inflator Challenge

Today you're a chemist! Create a chemical reaction that inflates a balloon without using your mouth. Only baking soda, vinegar, and a water bottle. Whose team can get the biggest balloon?

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Hosted at Sewell Mill Library & Cultural Center

The Fizz-Inflator Challenge was held on April 2nd, 2026 at Sewell Mill Library. Kids mixed baking soda and vinegar to inflate balloons through a real chemical reaction, competed to see whose balloon got biggest, and learned about acids, bases, and carbon dioxide gas. Completely free!

April 2, 2026 4:00–5:00 PM 2051 Lower Roswell Rd, Marietta FREE Event

7–11

Age Range

45 min

Duration

2–3

Kids per Team

FREE

Always Free

The Challenge & The Science

Goal: Use a chemical reaction to inflate a balloon on top of a water bottle. Whose team can get the biggest balloon?

The Science: Baking soda (a base) and vinegar (an acid) react to create carbon dioxide gas. The gas needs somewhere to go. Since the balloon is sealed on top of the bottle, the gas rises and fills the balloon. As more gas is created, pressure builds inside the bottle and pushes the balloon outward. This is similar to how yeast makes bread rise or how soda gets its fizz!

Chemical Reaction An acid (vinegar) meets a base (baking soda) and creates an entirely new substance: CO₂ gas.

Gas Expansion Carbon dioxide gas needs space. It rises out of the liquid and fills the balloon above.

Pressure As more gas is created, pressure builds inside the sealed bottle and pushes the balloon outward.

Real-World Connection This same reaction makes bread rise, soda fizz, and some fire extinguishers work!

Materials (per team)

1 empty plastic water bottle (16–20 oz, clear works best)
1 balloon (stretch it out first!)
Baking soda (about 2–3 tablespoons per team)
Vinegar (about 1/2 cup per team)
1 small funnel (or a rolled-up piece of paper)
1 spoon
Measuring cup
Markers or crayons (for decorating your balloon)
Tray or baking sheet (to catch spills)

Setup (5–10 min)

1Set up tables with materials for each team.

2Place a tray or baking sheet under each team's workspace to catch spills.

3Introduce the challenge: "Today you're chemists! Your mission is to create a chemical reaction that inflates a balloon without using any air from your lungs. Let's see who can make the biggest balloon!"

Build Steps (20–25 min)

1Prepare the Bottle: Use the funnel to pour vinegar into the water bottle until it's about 1/3 full (approximately 1/2 cup). Place the bottle on the tray so it doesn't tip over.

2Prepare the Balloon: Stretch out your balloon by blowing it up a few times and letting the air out. This makes it easier to inflate during the reaction. Decorate your balloon with markers! Give it a face, a team name, or cool patterns.

3Load the Balloon: Use the funnel to spoon 2–3 tablespoons of baking soda into the balloon. Be careful not to spill!

4Attach the Balloon: Carefully stretch the opening of the balloon over the mouth of the water bottle. Make sure the balloon hangs to the side so the baking soda does NOT fall into the vinegar yet. Check that the balloon is securely attached with no gaps or air leaks!

5The Reaction! On the count of three, lift the balloon so all the baking soda drops into the vinegar below. Watch the bubbles and fizz begin! The balloon should start to inflate as carbon dioxide gas fills it.

Test & Measure (10–15 min)

1Observe: Watch the reaction carefully. What do you see? What do you hear?

2Measure: Once the reaction stops (no more bubbles), wrap a measuring tape around the widest part of the balloon to measure circumference, or compare by sight.

3Record: Write down your results in the data table.

4Compare: Which team's balloon got biggest? What did they do differently?

Team Name	Balloon Circumference (cm)	Did It Work?	Observations
Ex: The Fizzers	32 cm	Yes	Lots of bubbles! Balloon got huge!
Team 1	___	___
Team 2	___	___
Team 3	___	___
Team 4	___	___

What Kids Learn (STEAM Links)

Science Chemical reactions, acids and bases, carbon dioxide gas, gas expansion, and pressure.

Technology Using tools (funnels, measuring cups) to conduct a controlled experiment.

Engineering Design process, controlling variables (amounts of ingredients), testing and observing results.

Arts Creative balloon decoration and team branding. Whose balloon face looks funniest when inflated?

Math Measuring volume (cups, tablespoons), measuring circumference, and comparing results across teams.

Digging Deeper: What is Carbon Dioxide?

Carbon dioxide is a gas that is all around us. We breathe it out, plants use it to make food, and it's what makes soda fizzy! This same acid-base reaction shows up everywhere in the real world.

Baking: When you bake a cake, baking soda reacts with other ingredients to create bubbles that make the cake rise. Without it, your cake would be a flat pancake!

Fire Extinguishers: Some fire extinguishers use carbon dioxide to put out fires because it smothers the flames by displacing oxygen.

Soda Fountains: The fizz in soda comes from carbon dioxide dissolved in liquid. When you open the bottle, the gas escapes, and that's the hiss you hear!

Safety & Tips

Do not drink the mixture! It's for science only.
Vinegar can sting if it gets in your eyes. Wash hands after handling.
Wipe up spills right away to prevent slipping.
Make sure the balloon is stretched out first. It inflates much easier!
Hold the balloon tightly onto the bottle so no gas escapes.
If your balloon doesn't inflate, check for leaks or try more baking soda next time.
It's okay if your balloon doesn't inflate! That's how scientists learn, by testing and trying again.

Troubleshooting

Problem	Solution
Balloon won't inflate	Check that the balloon is securely attached. Make sure baking soda actually fell into the vinegar. Try more baking soda.
Balloon inflates a little then stops	The reaction finished quickly. Next time, use more vinegar or more baking soda.
Balloon falls off	The opening wasn't stretched tight enough. Stretch the balloon more and press firmly around the bottle mouth.
Mixture bubbles over the top	You used too much baking soda or vinegar. Next time, use less or use a larger bottle.
Reaction is slow	Try using warm vinegar next time. It speeds up the reaction!

Extensions & Bonus Challenges

Temperature Test: Try using warm vinegar vs. cold vinegar. Which makes the bigger balloon? Why?
Amount Test: Experiment with different amounts of baking soda (1 spoonful vs. 3 spoonfuls). What works best?
Vinegar Test: Try different types of vinegar (white, apple cider, etc.). Does it change the reaction?
Bottle Size Test: Try using a smaller or larger bottle. Does the balloon inflate differently?
Timer Challenge: Which team can inflate their balloon the fastest?
Best Face Contest: Whose decorated balloon has the funniest expression when inflated?

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