Step 1: Step 1.
Fill an 8oz bottle 1/2 full with vinegar.
Step 2: STEP 2
Add 2 Tbsp. of baking soda into the balloon.
Step 3: STEP 3
Put the baking soda filled balloon on the top of the bottle that contains the vinegar. *Caution* DO NOT LET THE BAKING SODA GET INTO THE BOTTLE YET!
Step 4: STEP 4
And finally, slowly pour the baking soda into the vinegar creating a bubbling effect which turned into a gas which we all know as, Carbon dioxide which caused the balloon to expand.