The Bathtub Bottle Rocket

Bubbles from the reaction in the bottle will make the bottle move around the tub. Have children talk about solids, liquids, and gases. This can easily be repeated a number of times for fun. Try varying the amounts of baking soda and vinegar to see what changes. Be sure to record your results and share with us!


  • an empty soda (or water) bottle (with cap)
  • a straw
  • scissors (to poke a hole in the bottle and shorten the straw a little if necessary)
  • clay/putty/tape to seal the hole so no air or water will get in or escape
  • baking soda
  • measuring spoon
  • vinegar
  • measuring cup
  • toilet paper (just a few single sheets)
  • a bathtub


1. Take the scissors (or some pointed object) to make a small hole in the bottle (just large enough for the straw to fit into) down near the bottom.

2. Insert the straw into the bottle through the hole (one to one and a half inches).

3. Take the clay/putty or tape to seal the hole securely around the straw.

4. Fill up the bathtub about half full to prepare for the rocket launch.

5. Prepare the rocket for launching by pouring one fourth to one half cup of vinegar into the bottle.

6. Put a tablespoon of baking soda into a single square of toilet paper. Fold up the toilet paper into a small square, not too tight.

7. When you are ready to launch, drop the toilet paper into the bottle, place the cap on and shake it up. Quickly place the bottle into the tub with the straw down in the water.