Of Bottles, Balloons, & Sunny Afternoons: fun with science


My kids had a case of the grumps the other day.  They needed a serious redirection.

I sucked Br (4 y/o) in with “Want to help me with a science experiment?”, & Bl (20 mo) was sucked in by the sight of a funnel and the possibility we might be heading outside shortly…

Luckily, as with all good on-the-fly activities, most of us probably have these materials on hand.


  • bottle (we used an empty plastic soda bottle- 16oz size?)
  • balloon (we used a 12″ balloon, which I think is standard kids party size)
  • baking soda
  • vinegar
  • funnel (if you don’t have one, you can make a “temporary” one by twisting paper in to a cone shape)
  • optional: scoop (we have a giant bag of baking soda, as I use it for cleaning, etc., so we had to scoop the baking soda into the funnel)


We used a funnel to fill the bottle about half full of vinegar.  I had Br hold the bottle steady with both hands as I poured.  While this decreased the likelihood of a vinegar mess, it also helped Br get engaged and excited about what crazy thing Mommy may be doing…

Funnel in the balloon, to fill the balloon with baking soda
Funnel in the balloon, to fill the balloon with baking soda


Next, we filled a balloon most of the way full of baking soda. For us it took about 2 “scoops”- the scoop said it was 47cc (which is equal to 47 ml, or about 1 1/2 oz).  I found I needed to “help” the baking soda go down the funnel, so we poked carefully through the funnel (we used a cake tester, but any skinny thing long enough to go through the funnel should work) to help breaks up clumps & displace air so the baking soda goes down.

The vinegar-filled-bottle and baking-soda-filled balloon were escorted out to the driveway, as I figured there was a decent chance of a big mess.

While we were heading out, I discussed with Br what he thought might happen. (Great opportunity to reinforce the ideas of “hypothesis”/scientific testing).  I’ve had Br watch sometimes when I use baking soda & vinegar to clean a slow drain, so I reminded Br of that.

I asked Br: “what happened when the vinegar mixed with the baking soda in the sink?”

Br: “(pause)… Bubbles!”

Me: “so what do you think might happen when I dump the baking soda in our balloon into the bottle full of vinegar?”

Br: “(pause)… Bubbles!”

Let’s see!

It was pretty funny.  We were all surprised by how quickly the balloon blew up. I thought it might explode, and the kids instinctively ran up the driveway to safety! (My husband did remind me when he got home that I should probably invest in kid-sized safety goggles if I am gong to keep trying science experiments at home…)

Once we had assured ourselves the balloon was gong to hold, we re-approached. The kids were totally redirected now!!!

I explained to Br the balloon blew up because all of those bubbles couldn’t escape out to the air (vaguely alluding to the conservation of matter…).  We also observed a bunch of the vinegar ended up in the balloon, and it was pretty cold too ( I barely resisted talking about exothermic/endothermic reactions- but might be a good topic for older/more experienced “experimenters”)! We lifted the balloon up to dump it back into the bottle, which gave us a bit more fizzing.

I popped the balloon of, which sent it whizzing through the air & got the kids dodging back up the driveway.

Then they asked to do it again.

Awesome!!! (And just to reinforce the scientific method, I asked Br what he thought was going to happen THIS time when we put the baking soda in…)

Have you tried this? What did you think? We’d love to hear!

And do you know of any good resources to get kid-sized safety goggles? :)




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7 thoughts on “Of Bottles, Balloons, & Sunny Afternoons: fun with science”

  1. Oh yes! My kids love all things vinegar + baking soda! They fight over who is going to maintain the drains in the house! lol!

    Anyway, I’m stopping in because I am new to We Teach and just joined the “We’re Bloggers” group. When you find a moment, I would love for you to do the same. You can find me at http://sofiasideas.com/

    Sofia’s Ideas

  2. This seems simple and fun, right up my alley!! Thank you so much for sharing, I cant wait to try this with my kids (and the goggles do sound like a good idea, and a great opportunity for a really cute photo!!) :)

  3. i did this years ago when I was home-preschooling my nieces! They loved it too! Their eyes got so wide when they saw the balloon blow up! Have you made Flubber with your kids yet? That was another science experiment we loved to do.

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