Blowing up a balloon with baking soda and vinegar probably rates in the top 3 experiments I’ve ever done with the kids.
They got a kick out of this over and over, and over! The only thing that stopped them is that I ran out of baking soda (and we popped a few balloons).
Of course, any time you use balloons, always, always supervise the kids.
I’ve seen this done before, but it wasn’t until I read it in the Hands-On Science and Math book (affiliate link) and I shared 10 Hands-On Science & Math Activities that I actually did it with the kids. I don’t know why I put it off! Seriously one of the best ever experiments to do with the kids!
What you’ll need to blow up a balloon:
- plastic bottle
- baking soda
I took care of the prep work for the most part. I put a shot or two of vinegar in each plastic bottle. We had a set up for each of the kids.
I used a funnel to add a tablespoon of baking soda in each balloon. Then tightly secured the balloon onto the top of the bottle without letting the baking soda drop in yet, keep the balloon flopped over so it doesn’t spill into the bottle.
Note: Don’t add too much of either vinegar or baking soda, it could cause the balloon to erupt.
Then the experiment is ready to go!
The kids each took over from here. They each held tight to the balloon so that it wouldn’t pop off the bottle.
And then gently shook the baking soda out of the balloon and into the bottle.
And then they watched magic happen!
They were blowing up a balloon with baking soda and vinegar!
Of course, you could get into why that happens. When baking soda and vinegar mix it creates and gives off a gas (Carbon Dioxide) that blows up the balloon. Carbon dioxide is heavier than air though so it will not float in air if you release it. It is not as light as helium.
We repeated the experiment over and over again. We reused the balloons too, but eventually they ripped as I was spilling it over the neck of the bottle, which lost their seal.