HAPPY DUCKS:  CLASSIC DRINKING DUCKS ILLUSTRATE GAS LAWS, VAPOR PRESSURE, VOLATILITY, EVAPORATIVE COOLING, ETC.

Fill cylindrical dish to the brim with water.  Place ducks around the pond.  Soak heads to get started.

Additional discussion:

1. What is the role of volatility?
2. Why do they use Freon-11 instead of water?
3. Could a big duck be used as an evaporation driven motor?  This was once proposed to drive pumps along the banks of the Nile River.

©2000.  John Hart, University of Colorado