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This is an EASY activity I have been doing with my kids for the past 7+ years. I started doing this with my oldest son when he was 3 years old, and I am still doing it with my youngest daughter (and my oldest joins in and helps too). It never gets old – kids of all ages love seeing the foamy, bubbly chemical reaction and the surprise hidden colors.
This activity is so easy to set up, and you probably have everything you need at home: food coloring, baking soda, and vinegar. We’ve done this as a fun holiday themed science experiment by matching the hidden colors to the holiday. Here are some examples of hidden colors to use for each holiday:
- Valentine’s Day: pink, purple, and red
- St. Patrick’s Day: different shades of green or rainbow colors
- Easter: pastels – like pink, light yellow, light purple, and light blue
- 4th of July: red white and blue
- Halloween: black, orange, green, and purple
- Hanukkah: blue, white, and yellow
- Christmas: red, green and white
- Birthday: the child’s favorite colors
I’ve shared this activity 2 other times on my blog, but both times it was grouped with 2 to 3 other fun activities: 3 Valentine’s Day themed Baking Soda and Vinegar Experiments for toddlers and Summer Fun for Kids: 4 simple indoor & outdoor Rainbow STEM experiments. Every time I looked it up to do the activity with my kids I realized this activity was cumbersome to find within these posts, and it might not come up in a google search. I decided to give this experiment it’s own time to shine in this post because it’s one my family loves and comes back to again and again.
One thing I’ve forgotten to do with my toddler for the most recent time we did this activity was wear safety glasses. I always made my younger two wear them when we did science experiments when they were toddlers and they loved it! The loved science experiments mostly because they were excited to wear their safety glasses. Check out how cute my oldest two were in their safety glasses when they were 1 and 3 years old in the images below. Here is my Amazon affiliate link to these safety glasses that fit kids of all ages. We’ve loved them and used them for years!
I’ve shared this activity on my @engienering_emily Instagram account as a reel when I did this activity with my 2 year old for Halloween (it’s a good example of Halloween hidden colors). You can view the reel below:
Hidden Color Reveal with a Chemical Reaction
This is a perfect activity to spark a love of science in young children. In this activity children will learn about chemical reactions, work on fine motor skills by using the squeeze bottle, and identify colors. This is a fun observational activity for children ages 1+ and children ages 3+ years old will be able to participate.
Materials:
- Baking soda
- Vinegar
- Small bowls (around 10oz), one for each color of food coloring you’re using
- Food coloring
- Squeeze bottle or dropper
- Safety Glasses (optional)
Safety:
A chemical reaction occurs in this activity which creates CO2 bubbles. There is very small chance that the vinegar or baking soda used in this activity can splash into your eyes. If this happens, immediately flush the eyes with water until no longer irritated. To prevent this unlikely event don’t observe the reaction too closely, and/or wear eye protection.
Food coloring can stain clothing, furniture, and skin. Protect your work surfaces by covering them, and wear clothes you don’t mind getting wet and/or stained or wear an apron.
Procedure:
Tip: For the first time doing this activity, have an adult do steps 1-4 without the child present so the colors are a surprise. If you repeat the activity the child can help with these steps. Squeezing the food coloring and scooping the backing soda are good counting and fine motor skills practice for toddlers!
- Place 3 (or more) empty bowls on a table.
- Squirt food coloring (~4-6 drops) at the bottom of each small bowl. Use one color per bowl – you can choose colors to match holidays, colors the child is learning, of use their favorite colors.
- Completely cover the food coloring in each of the 3 bowls with a thin layer of baking soda (about 1-2 Tablespoons).
- Place the bowls on a tray (optional: this is to prevent spillage onto your table, alternatively you can use a table cover).
- Fill the squeeze bottle with vinegar.
- Ask the child to squeeze the vinegar slowly into each bowl one at a time to reveal the hidden color and watch it fizz, foam, and bubble due to the chemical reaction between baking soda and vinegar.
- Ask the child the identify each color as it is revealed.
STEAM Concepts Learned:
When the vinegar is poured onto the baking soda, a chemical reaction immediately begins. In the chemical reaction, carbon dioxide gas is released creating the fizz, foam, and bubbles. As the foam dissipates, the other products of the chemical reaction (water and a salt) remain in the cup, and the hidden color is revealed.
Young children are also learning to identify colors as they are revealed in this activity. It’s a great opportunity to introduce new colors or reinforce colors they have learned.
This is a family friendly STEAM activity that I know we will continue to do for years. I hope you try this activity and enjoy it as much as my family has. My son has helped both his sisters with this activity, and I cherish the great memories we’ve made doing this activity over the years.
You can also find this activity in several of the printable packs in my Shop: Chemical Reaction STEAM Activity for Kids, Rainbow STEAM Activities for Kids, Holiday STEAM Activities for Kids (each has it’s own variation to match the theme).
Have you tried this activity yet? Will you be trying it soon after reading this post?
