Acid Breath - Cool Science Experiment

An acid/base indicator that's made of blended red cabbage and water is used to demonstrate the various reactions that an acid/base solution goes through when some carbon dioxide gas is added. The best way to add the carbon dioxide is to drop a piece of dry ice into the solution. The color changes that result are quite amazing to see, and are caused by the changes in the pH levels that occur as more and more carbon dioxide gas is released.