Kids Science Experiments

Blowing up a Balloon

Blowing up a balloon sounds easy, doesn't it? But, what if I asked you to blow up a balloon without blowing into it with your mouth or using a machine? How would you get that balloon blown up?

Our Science Experiment

We are going to blow up a balloon without the help of a machine or our mouths.

Science Experiment 1

What you need

juice of 1 lemon -or- 1/4 cup vinegar
a balloon
empty soda pop bottle
2 tablespoons water
1 teaspoon baking soda

How to perform this experiment

Empty and clean out your soda bottle. Pour in the water and then the baking soda and allow soda to dissolve. Next, pour in the lemon juice (or vinegar). Quickly fit the balloon over the mouth of the bottle.

Watch!

The balloon begins blowing up (inflates)!

Why did it do that?

The baking soda is a base (alkali) and the lemon juice is an acid. When you mixed the two together, they created carbon dioxide which rises up. The carbon dioxide rose straight into your balloon and blew it up for you.

I wonder what would happen if

I wonder what would happen if I used an orange instead of a lemon?

Science Experiment 2

What you need

patience! (this experiment takes 2-3 days)
a very ripe (extremely brown) banana
a bowl
an empty soda pop bottle
a balloon

How to perform this experiment

Mash your old banana up in a bowl so there are no lumps at all. Squish the banana mixture into the soda pop bottle (a plastic spoon or knife might make this easier). Place the balloon over the mouth of the bottle. Put the bottle in a warm and sunny spot for a few days.

Watch!

The balloon begins blowing up (inflates)! Over the next few days, watch your bottle as it blows up the balloon.

Why did it do that?

Bacteria are eating your banana while it is rippening. The longer the banana remains uneaten, the more bacteria are present. They multiply and multiply as they consume the banana. While processing their food, bacteria give off gas. This gas is inflating your balloon.

I wonder what would happen if

I wonder what would happen if I used three bananas instead of just one?