The baking soda powered boat activity is easy and fun. I would say it is best for ages 6-9, although my 2-year-old thought it was really exciting to watch in the bathtub. The idea is to use baking soda and vinegar together to power a bottle boat through a body of water. We used the bathtub so the boat had a lot of room to travel and so it was easy for us to clean up. The length of this activity varies based on age, skill level, success rate, and interest in trying different approaches. It can last anywhere from 15 minutes to an hour or more!
Supplies:
- Empty plastic bottle (we used a one litter bottle)
- Baking Soda
- Vinegar
- Straw
- Scissors
- A craft knife
Step 1: Carefully cut a small hole in the bottom of the bottle near one edge, large enough to fit your straw through. My nephew decided exactly where to put the hole, which was great because when the experiment didn’t work we were able to talk about moving the location of the hole, amongst other things.
Step 2: Cut a piece of straw and poke it through the hole. Seal around the hole with a hot glue fun. Again, having your child decide how long or short the straw should be helps them feel engaged and in charge of their activity, especially if they aren’t old enough to use a hot glue gun yet.
Step 3: Hold the bottle level and pour in the vinegar. Make sure the straw is rotated so it is at the top, otherwise all the vinegar is just going to pour back out.
Step 4: Spoon in baking soda without dropping it into the vinegar. We did this by having my nephew put the baking soda in the bottle cap the first few times so that it mixed only once the cap was put on. Have fun experimenting with the best way to do this.
Before you combine everything, questions to ask:
- What do you think will happen when we combine the materials?
- How far you do you think the boat will go?
- Why does the boat move?
Step 5: Screw the top back on and combine the elements. Place your boat in water with the straw under water and watch it go!
This experiment has some great repeatability, especially if it didn’t really work the first time. Just rinse out your bottle, make adjustments as necessary, and add the ingredients again. I always love to ask what could be done to make it work better? We changed a lot of different parts of the experiment as we worked to make the best possible boat. Changing amount of the mixture, straw length, hole location, and even boat size are all different options. At 8, my nephew was really excited by this experiment and definitely wanted to do it again and again.
