The baking soda/vinegar balloons is a fascinating demonstration of acid base chemistry.
Vinegar is water with about 3 percent of a chemical called Acetic acid. Baking Soda is a compound called Sodium Bicarbonate, also known as Sodium Hydrogen Carbonate (NaHCO3
), and is a base.
So the reaction occurs:
Acetic Acid + Sodium Hydrogen Carbonate ---> Water and CO2
and Sodium Acetate (or more specifically, aqueous sodium ions and aqueous Acetate ions, but evaporate the water away and you should get sodium acetate, a salt -- sodium acetate is used to de-ice airport runways. It has the property that dry sodium acetate emits heat when it dissolves in water).
(carbon dioxide) is the gas thatís produced and that expands the balloon. The trick of the project is to get enough CO2
produced and to make the seal between the container youíre mixing the baking soda and vinegar in sealed well enough so the CO2
doesnít leak out. It takes some pressure to inflate a balloon, so some CO2
may escape if the seal isnít tight.
Carbon dioxide is heavier than air, the balloon wonít float in the air, but will fall to the ground or stay on whatever itís placed on.
Jason (and Tom)
(republished on 07/13/06)