Color Changing baking soda and vinegar science experiment
This color changing baking soda and vinegar science experiment is a fun way for children to observe changes in pH as the reaction occurs. It can take some time for children to understand both the concept of chemical reactions and that of pH. This experiment will help them to begin to explore both of these topics. It may then lead them (older children especially), to further investigations.
My son loves the bubbles that are made when baking soda and vinegar react. Since we first did this reaction, we have done a number of different vinegar and baking soda experiments. Each new experiment adds a layer of excitement and learning. By allowing children to explore this simple and safe reaction in a variety of ways, it helps them to ask questions, further investigate and make connections. These experiments build on one another and help solidify understanding.
Some preliminary baking soda and vinegar science experiments
Children can combine vinegar and baking soda with soap or in bags. These experiments will help them to become more aware of the CO2 that is produced. It will also help them to understand that new and different chemicals are formed as part of the reaction. Another approach is to do frozen vinegar or frozen baking soda experiments. This will help children to gain awareness of the role that heat plays in chemical reactions. The experiment in this post explores pH, in addition to chemical reactions. It can help children begin to explore the changes in pH that occur as part of the reaction. It may also help them begin to think about whether there might be ways to ‘prove’ that new and different substances are formed as part of the reaction.
pH- A simple summary / reference
The pH measures how acidic or basic (alkaline) a substance is and ranges from 0 to 14, with 7 being neutral. The pH measures the presence or absence of hydrogen ions. Acids and bases are created by the presence of charged ions (H+ or OH-) that help make up the chemical. Acids have hydrogen ions (H+) and bases have hydroxide ions (OH-). The greater the concentration of these ions, the more acidic or basic the substance. When an acid and base come in contact with one another, a chemical reaction occurs. They neutralize one another by breaking apart and reforming into new substances. Each time this happens, water (H2O) and a salt is formed.
There are some substances, known as indicators, which can help identify the pH of a substance. They do this by changing color in the presence of acids and bases. The way that they change color and at what pH(s) they change color, varies from indicator to indicator. Some natural indicators include purple cabbage juice, turmeric, grape juice, blueberry juice and blackberry juice.
What you need for color changing baking soda and vinegar science experiment
- Baking soda
- Turmeric, red cabbage (or another pH indicator)
- Trays, bowls, baking tins or pie tins
- Pipette or spoon
Mix in several spoonfuls of turmeric into half a cupful of baking soda. Add in one or two spoonfuls of water and then mix it together. We then spread the mixture out onto a tray. My son used a pipette to squirt vinegar onto it to see what happened.
Red Cabbage Indicator
Pour in several spoonfuls of red cabbage juice or spread out several spoonfuls of finely blended red cabbage leaves into a bowl or tray. I found it works best when there is just a thin layer covering the bottom. Then slowly add spoonfuls of baking soda in and stir until it all turns blue. You may add more of both if you would like to have a bigger reaction. Once we did this we used pipettes to squirt in vinegar. My son also likes to pour in a larger amount all at once to make a big reaction.
Questions to ask
- What changes do you notice when you combine the turmeric with baking soda? And the vinegar?
- What do you notice when you combine the baking soda and vinegar when the turmeric is present?
- Is there a difference when you start with the turmeric in the vinegar than when you start with it in the baking soda?
- Could you think of a way to prove that a new substance is created after the reaction? What could you do?
- What happened? Why do you think it happened? What did you learn?
- Is there anything more you would like to try out or test?
- What questions do you have about these reactions? Can you design an experiment to answer one of the questions?
What they get from it – Color Changing Baking Soda and Vinegar Science Experiment
As discussed above, this experiment can help children to explore the changes in pH that occur as part of the reaction. Children may also begin to think about whether there might be ways to demonstrate that new and different substances are formed as part of a chemical reaction. This hands-on activity will allow them to predict, observe, record and discuss, or present their findings. Doing experiments is an opportunity for children to write, by recording their observations with notes or with drawings. Children enjoy doing experiments and it can be highly motivational to write, even for more reluctant writers.
Research shows that people learn best (for long-term memory at least) when they learn through hands-on, practical experiences. (Hearns, Miller & Nelson, 2009; Hillman, 2011; Ferri, B.H., Ferri, A.A., Majerich, D.M., Madden, A.G., 2016). It’s also an opportunity for children to begin to develop scientific thinking. Furthermore, inquiry based learning will encourage children’s curiosity and love of learning. (Ambrose et al. 2010; Froyd 2008; Prince & Felder, 2007; Springer, Stanne & Donovan, 1999).
I know when I first started learning about atoms and ions, I found the abstract discussions about them completely baffling. It wasn’t until my teacher did some experiments, which demonstrated how some substances changed colour in the presence of different chemicals, that I was able to begin to make sense of it all. This experiment (and others discussed) won’t give children all of the answers, but they can be one of many pieces that help children put the puzzle together. While younger children won’t be able to understand the more complex aspects of this experiment, they will still have the opportunity to predict, observe, discuss and explain what they did and what they found.
Take it further
See my other vinegar and baking soda experiments so that children can explore chemical reactions. Baking Soda and Vinegar Painting Experiment for Kids (coming soon), Exploding bag baking soda and vinegar experiment, Colorful Baking Soda and Vinegar Experiment for Kids, Frozen baking soda / bicarbonate of soda and vinegar science experiment (coming soon) and Valentines STEM Art Projects for Toddlers and Kids. You may also want to see my post on pH (acid-base) indicators (coming soon).
It can be great for children to create their own experiments based on what they want to find out. Give them the opportunity to ask questions to extend their learning. Ask them: What questions do you have about these reactions? Can you design an experiment to answer one of the questions?
They may want to see if they can find the exact amount of vinegar to make the baking soda react. They might want to see if a frozen baking soda ball reacts faster with vinegar than dried baking soda ball. Alternatively, they may want to see if there is a difference in reaction between vinegar and citric acid.
Ambrose, S. A., Bridges, M. W., DiPietro, M., Lovett, M. C., & Norman, M. K. (2010). How learning works: Seven research-based principles for smart teaching. San Francisco, CA: Jossey-Bass. https://books.google.com/books?hl=en&lr=&id=6nGaDwAAQBAJ&oi=fnd&pg=PR13&ots=Kg0QTZYsS2&sig=-MfNhVTJDIr4BjQvPyIs1_j2N0o#v=onepage&q&f=false
Ferri, B.H., Ferri, A.A., Majerich, D.M., Madden, A.G. (2016). Effects of In-Class Hands-On Laboratories in a Large Enrollment, Multiple Section Blended Linear Circuits Course. Advances in Engineering Education, 5 (3). https://files.eric.ed.gov/fulltext/EJ1121997.pdf
Froyd, J. E. (2008). White paper on promising practices in undergraduate STEM education. Commissioned paper, Board on Science Education, National Academies. Retrieved from https://sites.nationalacademies.org/DBASSE/BOSE/DBASSE_080106#.UUoV5hngJ8g
Hearns, M.K., Miller, B.K. and Nelson, D.L. (2009). Hands-On Learning versus Learning by Demonstration at Three Recall Points in University Students. OTJR: Occupation, Participation and Health, 30 (4), 169-171. https://journals.sagepub.com/doi/10.3928/15394492-20090825-01
Hillman, C.N. (2011). The effects of hands-on learning versus learning by demonstration on memory in community dwelling older adults (Doctoral dissertation, The University of Toledo). Retrieved from https://pdfs.semanticscholar.org/6231/d55fc1c730ec086f012677c54141f466e18e.pdf
Prince, M., & Felder, R. (2007). The many facets of inductive teaching and learning. Journal of College Science Teaching, 36(5), 14–20. https://s3.amazonaws.com/academia.edu.documents/31566398/inductive_approach.pdf?response-content-disposition=inline%3B%20filename%3Dinductive_approach.pdf&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWOWYYGZ2Y53UL3A%2F20200221%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20200221T074538Z&X-Amz-Expires=3600&X-Amz-SignedHeaders=host&X-Amz-Signature=17a21f78b065bbe014fb696fbe440ea49e310fe9cdde81c9ebc1ac75d5c80ec2
Springer, L., Stanne, M. E., & Donovan, S. (1999). Measuring the success of small-group learning in college-level SMET teaching: A meta-analysis. Review of Educational Research, 69, 21–51. http://archive.wceruw.org/cl1/CL/resource/scismet.pdf