Dancing Raisins

As budding scientists we looked at the ingredients (baking soda, water, vinegar and raisins)for this experiment and made our own predictions as to what would happen when we made a mixture using these. We dissolved the baking soda in water and then added the raisins, followed by the vinegar. As soon as we added vinegar there was a big reaction! The mixture filled up with bubbles and totally overflowed on to the table! Then we noticed that the raisins began to rise to the surface of the mixture and they would go down again. After looking carefully and thinking about the reasons for this, we decided that the bubbles around each raisin made it lift up but once it got to the surface, those bubbles popped and the raisin once again sunk to the bottom until enough air was able to lift it up again.