Kid Science: Hot Air Balloon Bottle

Every year in New Mexico, the world’s premier balloon event takes place called the Albuquerque International Balloon Fiesta. The event runs from October 5-13 and is considered the largest ballooning event on earth! Over 600 hot air balloons will take to the skies and cameras will be at the ready. In fact, this event is said to be the most photographed event on earth, and the largest annual international event held in the United States.

Can’t make it to New Mexico? Why not have a little balloon fun of your own? Your children will love watching as their very own “hot air balloon” fills with air before their very eyes. You will only need a few things from your kitchen, so let’s get started!

You will need:

1 empty 2-liter bottle, cap removed
1 round balloon (preferably larger than 5″, see package for size)
1 sheet of paper towel
1 tablespoon baking soda
1 liter white vinegar
Food coloring (optional)

Begin by filling the 2-liter bottle halfway with white vinegar.

Cut or tear the paper towel into 4 equal pieces. Place one tablespoon of baking soda on the paper towel square.

Fold that square up burrito style. You want the baking soda to be inside so the reaction with the vinegar does not happen immediately, giving you time to add your balloon. Don’t wrap it too tightly or your children will get bored and tired of waiting for something to happen!

Drop the paper towel packet into the bottle and quickly add the balloon to the top of the bottle.

Watch as the balloon begins to fill with air as the vinegar penetrates the paper towel and reaches the baking soda.

So what’s happening here? Well, according to ThinkQuest, the acetic acid in the vinegar reacts with sodium bicarbonate (a compound that’s in baking soda) to form carbonic acid, the gas that fills the balloon.

You can add a few drops of food coloring to the vinegar for a fun colorful look. The food coloring does not affect the reaction or play any other part aside from adding color.

Hint: You can lift the bottle and swirl it around a bit to see if there is any baking soda left in your paper towel. If there is, you will see the reaction fizz again and it may even add more air to your balloon.

An alternative to using the paper towel is to add the baking soda to your balloon (using a funnel is helpful). Then carefully place the balloon over the top of the bottle, being careful not to let any of the baking soda leak into the bottle. When you are ready, lift the balloon and allow the baking soda to drop down into the bottle.

Amanda Formaro is a well-known craft expert and has been writing and crafting on the Internet for over fifteen years. Find out more on her blog, Crafts by Amanda, where she shares tutorials with step-by-step photos for adults and kids alike.