Fun with Dancing balls

Our Objective 

To observe the movement of naphthalene balls. 


The Theory 

In the experiment, when baking soda reacts with vinegar or Hydrochloric acid, Carbon dioxide gas is released. The density of naphthalene balls is more than that of baking soda so at first they will sink to the bottom. Then the Carbon dioxide bubbles rise and attach themselves to the rough surface of the naphthalene balls and increase their lightness. This makes the naphthalene balls rise to the surface, and the bubbles pop, releasing Carbon dioxide into the atmosphere. The naphthalene balls therefore lose their lightness and sink to the bottom of the beaker. Now they are too heavy and soggy to rise to the surface. The process continues until the gas is liberated after the gas bubbles on the surface of the balls disappear. 

Sodium bicarbonate, also known as baking soda or bicarbonate of soda, is a chemical compound with the formula NaHCO3 and the IUPAC designation Sodium hydrogencarbonate. A Sodium cation (Na+) and a bicarbonate anion (HCO3) combine to form this salt. Sodium bicarbonate is a white, crystalline substance that is commonly found as a fine powder. It tastes slightly salty and alkaline. 


Learning Outcomes 

  • Students learn about the reaction of baking soda and vinegar. 
  • Students will understand the role of Carbon dioxide. 
  • Students will be able to do the experiment in a real lab.