Blow up a balloon with gas!

It can be hard when you are little to blow up a balloon! But what if you can get a chemical reaction to do it for you?


Simply take…

  • A bottle or two with fairly thin necks, glass or plastic
  • Distilled white vinegar
  • Bicarbonate of Soda (lots as you will want to repeat this)
  • Balloons
  • Funnel
  • (doing this in your PJ’s is optional!)


Fill your bottle with 2-3cm of vinegar and set aside. Give the balloon a bit of a stretch (just as you would if you were blowing it up yourself). Put the balloon over the funnel and get as much bicarb as you can into the balloon (roughly 3-4 heaped teaspoon into the bottom but not into the neck as you need this to stretch over the bottle. You don’t want your bicarb to fall in while you are trying to get the balloon over so don’t make it really full).


Take the balloon off the funnel and stretch it over your glass bottle – being careful not to tip the contents into the bottle until you have got the balloon totally over the neck. (We had a few tear slightly at this point put if you can pull the tear down over the bottle a bit and hold your hand over the hole it will still work!) Gently tip the contents of the balloon into the bottle and be amazed!


It is a fairly fast and fun reaction!


We started small with several different colours (they wanted to know if different colours inflated differently). We then decided to experiment with a larger bottle and more vinegar. I love the look of wonder at this point!


It just kept growing and its a reaction which stays so plenty of time for silly photos.


So what causes the reaction? Essentially mixing the two substances together produces a chemical reaction and makes a gas…carbon dioxide. That gas rises and inflates the balloon. My biggest girl noted that this is how they get the bubbles into fizzy drinks. I love the connections they make through investigation.

Then we found the best balloon. Different shapes are the way forward.


It just made us all laugh…


We also got a bit technical towards the end as we looked at what effect bottle size had on the reaction. We measured the two sets of ingredients (same quantities of vinegar and bicarbonate of soda), took the same size balloon and make a hypothesis. I asked them what they thought would happen to the balloons? Both girls thought the bigger bottle would create a bigger balloon. It did! We concluded that more gas was allowed to be created in the bigger space, rising into the balloon. (I am not quite sure if this is right but either way it is a good lesson in keeping the variables the same to test a hypothesis – if there are any scientists out there I would love to hear why we got this reaction! I did say to the girls it could be because we can’t control one of the variables and one of the balloons might just have been that little bit bigger??? All good fun with lots of questions and discussion of the various concepts).

Enid Byton Rating: 7 out of 10 (A great way to show a chemical reaction and produce a proper wow!)


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s