To prepare for this experiment:
Fill your 16 oz plastic water bottle about 1/4 to 1/3 of the way with vinegar in advance before the party begins. Replace the lid and set aside in a cool, dry place until the party.
Fill as many balloons as you have water bottles (1 balloon per water bottle) with baking soda. Using a funnel fill a standard size balloon about half way (fill the rounded party, but not the straight end).
When you are ready for the experiment during the party give each child a water bottle and a balloon (you can use a twister to close the balloon if you are worried about the baking soda spilling out). Have the kids carefully attach the mouth of their balloon to the mouth of the water bottle. MAKE SURE that they balloon hangs to the side and the baking soda is still at the top of the balloon [SEE ABOVE PHOTO]. At the same time (so everyone experiences the “surprise” at the same moment), ask the kids to hold their balloon up straight with their fingers allowing the baking soda to fall into the water bottle (they can shake a little if they need to).
As the baking soda falls into the vinegar, the chemical reaction will cause the balloon to inflate!
It’s pretty fun to watch! Especially if everyone gets their balloons going at the same time!
Have fun! This experiment is an easy set up and clean up. It can easily be done inside the house as well! It will only work once. So, If they want to dry again, you have to wash out the water bottle and refill it with vinegar, and refill the balloon with baking soda!