Questions to Explore:

What happens when we combine an acid (vinegar) with a base (baking soda)?

How can we use a chemical reaction to inflate a balloon?

Materials:

Vinegar
Baking soda
balloon
water/soda bottle
tablespoon
funnel (or you can make your own paper funnel)

Procedure:

Pour 4 tablespoons of vinegar into a clear bottle (water/soda bottles work well)
Funnel a tablespoon of baking soda into a small balloon
Without spilling the baking soda, slip the mouth of the balloon onto the neck of the bottle
Lift the balloon up so the baking soda falls into the vinegar
The mixture will now begin bubbling and your balloon will inflate!

Here is a step by step experiment of the video courtesy of Education.com. You’ll notice that they pour the vinegar AND baking soda into the bottle rather than pouring the baking soda in the balloon. Either way will work! Click play to view.

Follow up Questions:

Does the temperature of the vinegar affect how big the balloon gets?

Does the size of the bottle affect how big the balloon gets?

Does more vinegar and baking soda affect how big the balloon gets?

Explanation

When we combine baking soda and vinegar, a chemical reaction occurs. A chemical reaction is when two chemicals react to one another and form a new chemical. In this case, baking soda and vinegar combine to form water, sodium acetate, and carbon dioxide. Because carbon dioxide is a gas and gas is less dense than liquid, it rises up and inflates the balloon.