For this experiment you need a few things.
1. Baking Soda
3. 20 oz pop bottle
7. Clothes Pin
Step 1: Step One
First you, fill the balloon with about 2 spoon fulls of baking soda, use the funnel to get it in the balloon. When done, clamp it securely with the clothes pin, so the soda does not come out.
Step 2: Step Two
Next, fill the pop bottle with vinegar to about half way between the bottom and the label.
Step 3: Step Three
Put the 'sealed' balloon on top of the bottle.
Step 4: Step Four
When you have it on securely, flip upside down and remove pin. Shake baking soda in to the bottle.
Step 5: Step Five
When all the baking soda is in with the vinegar let go and stand back and watch!