More Chemical Changes

While studying chemical changes, we did another experiement using corn, baking soda, and vinegar.

  We dropped the kernals of corn into a cup of vinegar.  We then poured the baking soda into the cup.  When the vinegar and baking soda were mixed together, a chemical reaction occured between the  acid in vinegar and sodium in baking soda. This caused a release of chemical energy and the formation of carbon dioxide. The gas bubbles that formed adhered to the outside of the popcorn kernels and raised them to the surface of the vinegar. This happened because the kernels and bubbles together had a lower density than water and thus rose to the surface of the liquid. At the surface the gas bubbles burst, releasing the carbon dioxide into the air. Once the bubbles had burst, the density of the kernel was once again greater than that of water and the kernel fell towards the bottom of the glass. This cycle repeated itself over and over.  It was so much fun to watch.