Can you blow up a balloon without using your mouth? In this simple science experiment, we’re going to show you how to do it with only a few everyday items you probably already have in your home. It makes a great experiment for young children because the set-up is simple and it only takes a few minutes to get to the exciting finale.
In addition to a video demonstration and detailed printable instructions, we also have the scientific explanation of how this simple chemical reaction works making it perfect for older scientists too.
- Small Soda Bottle
- Baking Soda
Step 1 – Start with some questions: How do you blow up a balloon? What if I told you that you couldn’t blow air into it, do you think you could still inflate (blow-up) the balloon? Then observe the supplies for the experiments. Do you think they can be use to blow up the balloon? If so how? Write down your hypothesis (prediction).
Step 2 – Using a funnel, pour about a third of a cup of vinegar into the bottle. We used Apple Cider Vinegar, but any type of vinegar will work.
Step 3 – Then insert another funnel into the mouth of the balloon. We recommend using two different funnels. One funnel for filling the bottle with vinegar and one for the balloon. However, you can do the experiment with only one funnel. Just make sure you completely wash and dry the funnel after you add the vinegar and before you put it into the balloon. This is very important.
Step 4 – Place two teaspoons of baking soda into the funnel so it falls into the balloon. When the balloon is filled with the baking soda, carefully remove it from the funnel.
Step 5 – Next, secure the mouth of the balloon over the mouth of the bottle. Take your time doing this and don’t let any of the baking soda fall out of the balloon and into the bottom of the bottle. Take a moment to make some observations. What will happen if we lift up the balloon? Write down your hypothesis (prediction) and then test to see if you were right!
Step 6 – While holding the bottle, lift the end of the balloon and allow the baking soda to drop into the bottle.
Step 7 – What happens to the balloon? Was your hypothesis correct? Wondering what caused the balloon to inflate? Find out the answer in the how does this experiment work section below.
When baking soda (a base) and vinegar (an acid) are mixed together they create a chemical reaction that results in the formation of carbon dioxide gas. Gases do not have a specific shape or volume, rather they expand rapidly filling their container. Gases expand rapidly because their particles move at high speeds in all directions. As the carbon dioxide gas fills the bottle, it has nowhere else to go so it begins to fill the balloon. As the carbon dioxide gas fills the balloon, the balloon inflates. The more gas that is created, the larger the balloon will inflate.
The baking soda and vinegar chemical reaction will continue to inflate the balloon as long as there is still baking soda and vinegar to react. Once the reaction between baking soda and vinegar has stopped, the balloon will slowly begin to deflate.
An acid is a substance that tastes bitter, reacts with metals and carbonates, and turns blue litmus paper red.
A base is a substance that tastes bitter, feels slippery, and turns red litmus paper blue.
Other Ideas to Try
Does changing the amount of baking soda and vinegar change the size of the balloon when it inflates? What would happen if you used another acid like lemon juice instead of the vinegar? Would it react the same with the baking soda?
I hope you enjoyed the experiment. Here are some printable instructions: