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Explosive!


There comes a point in every kid’s life when they discover the magic of mixing baking powder and vinegar. I’ll leave volcanoes for 5th grade science projects and show them something more interesting to 3- and 5- year olds and more contained – a self-inflating balloon.

With the leftover balloons abound and the awesome gift giving of Briana’s friends, we are armed and ready for our experiments today. One of Bree’s friends got her a science kit and she cannot wait to use it. We do one of the water experiments on density (if you want to do it at home take some clay or playdoh of the same size, wad one bit of it up and watch it sink, then shape the other bit of it into a boat and watch it float. Talk about the water displacement even though the weight is the same).

Then Bree wants to do another one. I try to convince her not to do all of her experiments at once, but it’s her gift and she insists. We make paper airplanes and I’m surprised how much they remember about Bernoulli’s principle and thrust (My ‘Take Flight’ blog is here - http://pedigreedhousewife.blogspot.com/2011/11/take-flight.html).

Briana’s fun with her science kit is not over yet. Luckily her kit comes with about 20 experiments so we can have tons more fun. Anyway, we come across an experiment on carbon dioxide that shows how to make balloons self-inflate, which I expand on (oh yeah, I love the puns). Only I would think a science kit needs additional elaboration. That’s ok. I own it.

I want the kids to understand why the balloons can self inflate, so out comes a big can of baking powder, a jar of vinegar and a bowl. I let Abby scoop some baking powder into the bowl and then I let Briana pour a tiny bit of vinegar over the top.  At first not much happens. Then a stream of bubbles form right before our eyes.


Then I shake the bowl and bubbles fill the bowl to the screaming, jumping glee of the kiddies.

I explain that the bubbles are carbon dioxide that is being released from the mixture. “Plants eat carbon dioxide” says an astute Briana. I’m surprised that she remembers the association with plants taking in carbon dioxide and releasing oxygen. Then Abby says, “No, Briana. Plants eat OUR carbixide when we breathe it on them.” Great understanding Abby…if not great pronunciation. I break the words down for them: CAR-BON-DI-OX-IDE. Now we can all say it correctly.

I then tell them that the carbon dioxide bubbles out of the mixture until all of the vinegar and baking powder is mixed and the CO2 is used up. We watch and wait for the bubbles to stop forming and die down a bit. That is what is happening inside the balloons. The carbon dioxide is released and trapped in the balloon. The balloon stretches when bubbles get big, like they did in the bowl, and push on it.

For self-inflating balloons, here’s what we did:

Step 1: Blow up a balloon and let the air back out (just to stretch the balloon).

Step 2: Put a funnel in the top of the balloon.


Step 3: Pour in 2 tablespoons of baking powder, followed by 2 tablespoons of vinegar. You can adjust the amounts for how much CO2 you want to release. I didn’t want the kids balloons to get too big or pop, so I went small.


Look how brave I am! My cordless phone and my Nook are right next to us on the table. No electronics were harmed in this experiment, though I wouldn't recommend supervising the pouring of vinegar with one hand and half of your attention while taking a picture with the other hand.


We did Briana’s balloon all the way first and then Abby’s. I am slow closing Bree’s balloon as I gab about what is going on and take pictures and it got a bit messy, so Abby is a little hesitant until the balloon is closed up. Once it is closed though, she shakes hers eagerly.

Step 4: As quickly as you can, tie off the balloon! Then shake it up and watch the balloon grow.


If you look closely, you'll see Abby and her un-inflated balloon in the corner of the picture. Look at the size difference between Bree’s balloon and Abby’s, while Abby waits for her turn! And Briana is still shaking hers up.


Then we talk about why the balloons stopped getting bigger – the reaction has come to completion and all of the carbon dioxide has been released. The next morning the kids notice that the balloons have shrunk a little bit, “just like when the bubbles popped and got smaller in the bowl”.

At dinner that night, Daddy has a soda. My kids start screaming, “Daddy! The carbon dioxide is being released! Daddy look! Don’t worry, it won’t keep fizzing forever you know.” Understanding is a powerful thing!

For more fizzy fun, check out my ‘Fizzling Out’ blog post - http://pedigreedhousewife.blogspot.com/2012/04/fizzling-out.html

<3 Pedigreed Housewife 

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