PURPOSE: To show the difference in density between soft drinks with and without sugar.
DESCRIPTION: Unopened cans of Pepsi and Diet Pepsi are floated in a bath of slightly salted water. The Pepsi sinks, while the Diet Pepsi floats. The density of the Pepsi is increased by the dissolved sugar, which occupies space between the water molecules. Diet Pepsi has no additional sugar, and is therefore less dense.
SUGGESTIONS: Ask your students the question: When you dissolve a cup of sugar in a cup of water, do you get two cups of solution?
REFERENCES: (PIRA unavailable.)
EQUIPMENT: Cans of Pepsi and Diet Pepsi, tank with salted water.
SETUP TIME: 5 min.
Go back to Lecture-Demonstration Home Page.