Kids love mixing baking soda and vinegar together. There is just something about watching the bubbling reaction between the two.
That’s probably why there are so many fun kids science activities involving vinegar and baking soda.
You can use that chemical reaction for more than just a fizzy science experiment. Incorporate it in one of our favorite STEM activities for kids.
Your child will love using baking soda and vinegar in this simple bottle rocket boat STEM activity.
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Awesome Engineering Activities for Kids
If you enjoy this kids engineering activity, then you are going to love my new book, Awesome Engineering Activities for Kids.
The book will challenge and engage kids ages 5-12 with over 50 exciting hands-on projects.
Each challenge contains simple step-to-step instructions and an explaination of all the hows and whys. You will also find ways to extend each activity, and an explanation of all the STEAM components involved.
It’s much more than just an activity book. Your child will be having fun and learning, using materials that you probably already have at home. 
Bottle Rocket Boat STEM Activity
Once you try this one, you may want to check out our rubber band boat and give it a try!
Materials Needed:
- Clean, Dry Disposable Water Bottle with Lid
- Bendable Plastic Drinking Straw
- Vinegar
- Baking Soda
- Small Sharp Knife
- Measuring Cup
- Tablespoon
- Craft Foam
- Duct Tape
- Bathtub or Large Plastic Container with Water
How to Make a Baking Soda & Vinegar Rocket Boat
Use the tip of a sharp knife to cut a small X in the center of your water bottle’s lid. This step should be done by an adult, or under close adult supervision.
Thread the short end of your bendable straw through the lid so that the shorter end will be inside the bottle when the lid is put back on. You may need to use the tip of a pen to help widen the hole a bit more so you can wiggle the straw in.
You want the straw to fit snugly, without gaps for air to escape through. If there are any gaps, use a small amount of duct tape to cover them.
Next, cut 2 triangles from craft foam. If you want, you can decorate them with permanent markers. These will become the fins for your rocket.
Duct tape the fins to the sides of your bottle so they are opposite of each other.
Ready to test out your boat STEM activity?
Fill a bath tub (or large plastic container) with 4-6 inches of water.
Pour 1/4 cup of vinegar into the plastic bottle.
Now for the tricky part. Tilt your bottle so the vinegar stays at the bottom and you can scrape a tablespoon of baking soda into the top of the bottle without it falling into the vinegar.
You may need to push the baking soda off the tablespoon with your finger. This is where having a helper really comes in handy!
Keeping the bottle tilted, screw the lid back on. Make sure the lid is on tight so no air can escape.
Give the bottle a quick shake and place it in the water so the end of the straw is just below the water’s surface.
Your water rocket boat will move across the water.
Why the Baking Soda Vinegar Boat Works
When the vinegar and baking soda mix it causes a chemical reaction.
This reaction produces carbon dioxide, which is a gas. The gas has to escape the bottle, so it pushes through the only opening—the straw.
The escaping gas pushes against the water, causing your boat to go forward. It’s a fun example of Newton’s 3rd Law of Motion, which rougly states, “For every action there is an equal and opposite reaction.”
Extensions for the Boat STEM Activity
Want to take the learning even further?
- Try changing the amount of vinegar you use. Does it affect how far the boat moves?
- What if you change the amount of baking soda?
- Try making a bottle rocket and seeing how high it will fly into the air.
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