The Carbon Dioxide Spiral Staircase
The demonstration where CO2 is generated and used to snuff out a candle in an aquarium or other container is well known. This article describes a dramatic variation on these demonstrations that allows for discussion of such topics as the ideal gas law, densities of different gases, gas density changes with temperature, miscibility, and viscosity. The device described is easily and inexpensively produced and stored. The demonstration is large scale and works well for classrooms and community outreach events.