Sink or Swim: The Cartesian Diver

In this Activity, students assemble a Cartesian diver and observe the effects of changing the pressure and temperature. An optional extension challenges students to cause the diver to hit the bottom in one minute by connecting the diver bottle to a second bottle in which baking soda and vinegar are reacted. The Activity illustrates relationships among pressure, volume, temperature, and buoyancy. It could be used in connection with the concepts of gases and liquids and discussions of Boyle's, Charles', and the ideal gas laws. The optional extension could be a chemistry recruitment exercise or a year-end project.