Windex or ammonia 1 tsp. Then, place it in the plastic bag. This will be your indicator solution. Pour equal amounts of juice into the cups. The changes in color tell you a chemical reaction has taken place.
Many cleaning products are basic.
In order to know that a reaction took place, we need to have something to compare. That's why we didn't add anything to the cup labeled cabbage juice. Test out other substances to learn more about acids and bases. Try other indicators like radishes and grape juice as indicators.