Ready, Set, Reaction!


In search of the perfect ratio!



20-30 minutes

Grab a partner and prepare to apply your newly discovered chemical reaction skills to produce a perfect CO2 reading every time.   Good luck!


In our previous experiments we discovered that CO2 is produced in an endothermic reaction between baking soda and vinegar.  We also learned that changing the ratio of these two reactants could dramatically change the reaction.  Prepare to dive deep into your new knowledge and design the perfect ratio of reactants to give you the same awesome results, time after time.  Good luck!!


By completing this experiment and conducting the scientific observations associated with it you will master the following knowledge! Good luck science explorer!

  • A physical change does not change the composition of a substance, only its form (state of matter).
  • Different types of substances can “react” with one another to create a chemical change in the substances.
  • Chemical Reaction:
    • When two substances react with one another to create a new, different substance.
    • Causes a change in the composition of a substance.
    • Can cause physical and chemical changes in substances – even creating gas where there was none before.
    • Can require energy (endothermic) to take place or produce energy (exothermic).
  • CO2:
    • An invisible and odorless gas.
    • Heavier than air
    • Exhaled by human beings.
    • Levels can vary in the air around us depending on many factors.
    • Can be generated through a chemical reaction of baking soda and vinegar.
  • The pH scale tells us if a substance is a base or an acid.   
  • Vinegar (acetic acid) is an acid and baking soda (sodium bicarbonate) is a base
  • A ratio is a numeric comparison of one amount to another. A percentage is a ratio based on a scale of 100.
  • Scientific sensors allow us to measure the scientific world around us with better precision and accuracy.

What You'll Need

  • IOS or Android smart device with Bluetooth Low Energy (BLE) to connect to databot™
  • databot™ + Phyphox App installed on your smart device.
  • Baking soda (Sodium Bicarbonate)
  • Vinegar (Acetic Acid)
  • Container with an airtight lid.
    In the activity demonstrations we are are using an OXO brand, 4 liter, storage
    container that has a push button airlock feature.  
  • Measuring cups, spoons, or graduated cylinder for measuring quantities
  • Glassware – low profile drinking glass or beaker for the reactants that will fit within your airtight container along with databot™.
    The glassware used in our demonstration to contain the reaction is a 250 ml beaker and this is  adequate for the reaction. Study the video to better understand what you will need.
  • Stopwatch or clock for timing 3 minute run



  • Complete PDQ 1 and Experiment to clearly understand the dynamics of this chemical reaction
  • Review your results from the Experiment to prepare yourself.

Collaboration (25 Mins)

Your challenge as a team is to create the perfect ratio of your Acid-Base reactants to meet this challenge:

  • You will have a timed run of 3 minutes with the time beginning when your airtight lid is sealed.
  • You must select the appropriate amount and ratio of your reactants to fill your chamber with CO2 to a level of 10,000 PPM.  Your reading is taken at 3 minutes!

If you are in a classroom or group, you can compete to be the closest to 10,000 ppm.  Good luck!

Awesome! This concludes your Chemical Reaction investigation.

Ready for another? Let’s go!

Next Step, Ready to Explore?

Educator Info

Educator Info

Ready, Set, Reaction! by Robert O. Grover & Team databot is licensed under a Creative Commons Attribution 4.0 International License. Permissions beyond the scope of this license may be available at