- Baking soda
- White vinegar
- Plastic bottles
- Hot glue
- Baby pool or bathtub
What to do?
- 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.
- 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 safe distance, to make sure bits of plastic don’t fly into your eyes).
- Place a 10 cm straw into the hole so that about 2 cm of the straw 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.
- 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 spoonful 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!
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.
Source: Red Tricycle