Fizzy Balloons

 - by KitchenPantryScientist


I was never an enthusiastic chemistry student.  That being said, I have to admit that chemical reactions can be lots of fun to watch as things turn colors, make bubbles, or smell different.  They can change from liquids to solids and they can even explode.

There are many fun, safe chemical reactions you can perform with your kids.  I’d recommend having them put on safety goggles or sunglasses, if you have them, for most experiments where you mix things together.  As you can see, my children aren’t wearing any eye protection for this project, but I did have them stand back to make sure the balloon wouldn’t explode the first time we did it.  Just use common sense.


You will need: a balloon, an empty soda bottle, white vinegar, and baking soda.  Put 1/4 to 1/2 cup vinegar into the soda bottle.  Then, hold the mouth of the balloon open and have your child pour about a teaspoon of baking soda into the balloon.  Shake the soda into the “bulb” or the main part of the balloon.  Then,  stretch the mouth of the balloon over the mouth of the bottle, trying to keep the main part of the balloon off to the side (so the soda isn’t dumped into the bottle right away.)  Ask them what they think will happen when you mix the two things together. Finally, let your child shake the soda into the bottle, all at once.


Stand back and watch what happens!

If the seal is tight, which it should be, the reaction between the soda and the vinegar will form a gas that inflates the balloon.  Our balloon was big enough that it didn’t explode, but if your balloon is over-inflating, simply take it off of the bottle.  Just pay attention and you’ll be fine.

What happened?

Baking soda is a chemical called sodium bicarbonate. Vinegar is called acetic acid. These two chemicals react to form some different chemicals.  One of these is carbon dioxide gas.  This is called a chemical reaction.  The gas is what inflates the balloon.  We know a reaction is happening because we can see bubbles forming.

What else do your kids notice about the reaction?  Have them record (or help them to record) what they see in their science notebooks.  Older kids can draw what they see and then try to describe it.  My kids loved it when I wrote down their descriptions for them before they could write. Have them touch the bottle.  Does it feel warmer or cooler than room temperature?  A temperature change is also a clue that a chemical reaction is occurring!  They could even time how long it takes for the balloon to inflate.

My kids did this experiment three times and would have kept doing it all day.  They thought it was pretty great.  Give it a try!  Put those budding brains to work!

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