This has to be one of the most fun science activities I’ve done with my kids in a long time. It is super simple, inexpensive, and quick. It took us a few tries experimenting with how to add the baking soda to the bottle, but I think we got it down. We were able to make this super easy bottle rocket launch higher than our 2 story house four times in a row.
This experiment was inspired by our astronomy curriculum from Pandia Press (NOT an affiliate link, but a great curriculum). The primary change that we made between the instructions in that curriculum and our final version was to use a Kleenex instead of a paper towel. Also, as we were inserting the baking soda-filled tissue into the bottle, we ripped off the end of the tissue as described below to cause the mixing to occur more quickly.
- 2 liter bottle
- baking soda
- #4 rubber stopper
- measuring cup
- 3 pencils
- packing or duct tape
- Kleenex or other tissue
- funnel (not pictured)
- Place rubber stopper into empty 2-liter bottle.
- Put a piece of packing or duct tape near end of unsharpened pencil opposite eraser.
- Stand 2-liter bottle on rubber stopper and tape pencil to bottle so that it touches the ground.
- Repeat previous steps by taping a second pencil to 2-liter bottle.
- Repeat previous steps again to tape a third pencil to bottle. Adjust pencils if necessary to make sure all 3 erasers are touching the ground and bottle is more or less vertical.
- Measure 2 cups of vinegar.
- Use a funnel to pour 2 cups of vinegar into bottle.
- Use a measuring spoon to place 2 tablespoons of baking soda onto a facial tissue.
- Fold tissue in half to get baking soda to gather along the center crease.
- Fold bottom of tissue paper up as shown to hold in baking soda.
- Fold side of tissue over as shown.
- Roll up the tissue as shown into a tube that will fit into the opening of the 2-liter bottle. The final packet should look something like this.
- Start inserting the backing soda packet into the opening of the 2-liter bottle.
- Continue pushing tissue packet into bottle being careful not to let it fall in.
- When packet is almost completely into the bottle and the remaining part outside the bottle contains no baking soda, use the stopper to hold the packet in place. Rip off the remaining tissue that does not contain baking soda and let the packet fall into the bottle.
- Give the bottle a quick shake and turn it over so that stopper is at the ground.
- Wait patiently. This never took more than 60 seconds for us.
- Watch the rocket launch! And continue to rise…. After perfecting our baking soda packet and insertion method, every launch went higher than our roof!
Have fun being a rocket scientist!