Experiment you will be able to watch a chemical reaction. In this experiment vinegar (a substance) and baking soda (a substance) will mix together. When mixed together the molecules of the two substances will re-arrange, or change, to make new substances.
Vinegar has acetic acid in it. The chemical name for baking soda is sodium bicarbonate. When you mix the two together you get sodium acetate and water. You also get carbon dioxide, which is a gas. The bag puffs up because carbon dioxide is a gas and takes up a lot of space. Eventually the bag isn't big enough to hold all that carbon dioxide gas so it explodes!
