
It’s never too early to introduce a child to the wonders of science! Here’s an example of a multi-step reaction that’s super simple, extremely cheap, and a great summertime activity for your toddler.
What you’ll need:
- 1 Pyrex dish
- 1 box of baking soda
- 1 bottle white vinegar
- liquid food coloring
- plastic dropper bottles (I bought some on Amazon here but you can find droppers at dollar stores – or you can use cheap plastic bowls for each color. Just fill them up as if you are going to dye Easter eggs. Then, use a spoon instead of a dropper when you add the vinegar.)
Cover the bottom of the Pyrex dish with about ¼” or ½” of baking soda. (You can use more if you want!)
Pour vinegar into the dropper bottles and add food coloring to each one.
Give your child the colored vinegar droppers and let them drip it into the dish with the baking soda.


Ta da! Bubbly fizzy colors!
What’s happening here is that the acetic acid in the vinegar reacts with the sodium bicarbonate and forms carbonic acid. Carbonic acid is unstable, and immediately decomposes into carbon dioxide and water. That’s what causes the bubbles!

Bonus: if you’ve put in an extra thick layer of baking soda, you can stir the colors up and maximize your fizz.
Have fun!
We LOVE playing with vinegar and baking soda! I introduced it to my son last year on the Fourth of July (it was the closest thing to fireworks I could think of for a toddler to do!) and he had the best time. This year, we created some baking soda trains for him to “paint” and it made it even more fun: http://play-trains.com/fizzy-engine-baking-soda-and-vinegar-trains/