How to Make a Baking Soda Vinegar Powered Steam Boat

This simple experiment is a perfect outdoor activity for summer.

By Melissa Heckscher July 1, 2020

Looking for a fun science experiment to keep your little Einsteins busy? This simple baking soda and vinegar experiment is a perfect outdoor activity and demonstrates how a chemical reaction can really get things moving. Read on to find out to discover how to make a baking soda vinegar powered steam boat.

You’ll need:

– Baking soda

– White vinegar

– Plastic bottles

– Straws

– Sharpeez (optional) for decorating the boat

– Hot glue (not pictured)

– Baby pool or bathtub (not pictured)

Step 1: Decorate your “boat.”

Take the labels off the plastic bottles and let your kids decorate their “boats” using permanent or (oil-based) paint markers. This is optional, but fun—especially if you’ve got more than one little captain at the helm.

Step 2: Drill a hole in the bottom of the boat—then put a straw in it.

Using a drill or soldering tool, make a small hole (the size of a straw circumference) in the bottom edge of your plastic bottle. Caution: Wear safety glasses—and keep kids at a distance—to make sure bits of plastic don’t fly into your eyes).

Place a three or four-inch straw into the hole so that about an inch of sticks into the bottle and the rest sticks out the back). To secure the straw so that no liquid drips out the sides, apply hot glue around the edges.

Step 3: Fill it up and watch it go!

Turn the bottle sideways, and cover the straw end with your fingertip while you pour about 1 cup of vinegar into the bottle. Then, keeping the bottle flat and the straw side up (so nothing spills out), drop a few spoonfuls of baking soda into the bottle. Make sure to keep the baking soda on one end and the vinegar on the other.

Give the bottle one quick shake, and place it quickly into your pool or tub. And it’s off!

The science of it: What’s happening?

When vinegar (an acid) meets baking soda (an alkali), they react to form a gas (carbon dioxide). This gas must escape the bottle, so it pushes out through the straw, which in turn powers your boat across the pool. Once all the gas has escaped, your boat slows down.

Step 4: Tinker with the steps (and let your kids take over!).

Now that you’ve done the experiment once, it’s time to hand over the ingredients to your kids. Let them try to figure out (on their own, hopefully!) how to get the boats moving as fast as they can. Some things kids can explore include:

– Does more baking soda change how fast the boat moves?

– Does more vinegar change anything?

– What about how you combine the ingredients? For instance, does a quick shake help things move? Or a slow fizz?