Naphthalene Balls Dancing

MATERIALS :

• 500 ml beaker
• 400 ml water
• Sodium bicarbonate
• Citric acid
• Naphthalene ball

PROCEDURE :

• Take a 500 ml beaker add sodium bicarbonate ,citric acid and 400 ml of water. Cover the beaker with lid.
• Put naphthalene balls into the solution. The balls go up and down. It's look like a dance.

WHY ? 

            Sodium bicarbonate react with citric acid to evaporate carbon dioxide gas. So that the naphthalene balls going up and down.