Chemistry Rocket

There is so much fun to be had with good old baking soda and vinegar reactions. When mixed together a gas called Carbon Dioxide (CO2) is produced. Gas atoms love to spread out and take up lots of space. This make CO2 the perfect fuel for a chemistry rocket.  

WARNING: Wear safety goggles and make sure you set this experiment up away from windows, cars, people and anything else of value. The acid may also damage your grass. Adult supervision required. 

You will need: 

  • Small bottle with push up lid  (Pump Bottle works best here)

  • Pint glass (plastic)

  • Vinegar (White or Malt)

  • Baking Powder (2 teaspoons)

  • Half a sheet of kitchen roll. 

  1. Make sure the bottle is water tight and that the lid can be pushed up and down easily. We want to make sure no liquid can escape. 

  2. Fill the bottle half way with vinegar.

  3. Measure two teaspoonfuls of baking soda onto the kitchen roll and roll the up to look like a sweet wrapper. This will allow a delay in the reaction so you can run away. 

  4. Insert the baking soda packet into the bottle and seal the lid extra tight. Make sure the push up lid is also all the way down. 

  5. Give the bottle a gentle shake and place upside down in the pint glass ready to launch. Now run away and enjoy the rocket launch. 

What is happening here? 

As the baking soda and vinegar mixes a gas called Carbon Dioxide is produced. This gas is expanding very quickly inside the sealed bottle, building up pressure. When the pressure becomes too much the gas forces to push up lid to open and powers the launch. This launch demonstrates the 3rd Law of Newtonian Physics: for every action there is an equal and opposite reaction. The action was the energy being built up inside the bottle. The opposite reaction was the release of gas through the lid that propelled the rocket. 

Science Challenge

Can you get your rocket to fly higher/lower by changing one variable at a time: 

  • An extra spoonful of baking powder? 

  • A spoonful less of baking powder? 

  • A different size of bottle? 

  • More/less vinegar?