Pour ½ cup of white distilled vinegar into a plastic freezer bag with a zip closure. Use a medium to large freezer bag for this carbon dioxide experiment.
Pour 2 tsp. of baking soda inside the plastic bag.
Close the plastic bag quickly with the zip closure. Make sure to close the bag securely, because air will prevent the vinegar and baking soda from reacting.
Hold the bag away from your face and watch it inflate. The pressure will build and cause the zip closure to come apart with a "pop."