gases

Nail Bottle Demonstration in Slow Motion

The nail bottle demonstration is one that many of us have conducted in our classes. To perform this demonstration, 2 – 3 mL of ethanol is placed into a plastic bottle that has two nails punctured into opposite sides of the bottle. After stoppering the bottle, a Tesla coil is touched to one of the nails. A spark jumps from one nail to the other, which initiates the combustion of vaporized ethanol inside the bottle. We recently filmed this reaction with our high speed video camera.

How Heavy Is a Balloon? Using the Ideal Gas Law

In this Activity, students explore buoyancy with helium-filled Mylar balloons. They use the ideal gas law to predict the mass of the balloon if it were empty, compare it to the actual mass of the empty balloon, and discuss experimental sources of error. This Activity demonstrates the ideal gas law and introduces students to the concept of buoyancy.

Where There's Fire There's...

In this Activity, students compare the combustion of different substances such as a glowing wooden toothpick and lit birthday candle in air, oxygen, exhaled breath, and carbon dioxide environments. The oxygen and carbon dioxide are generated from supermarket chemicals. This Activity can be used to explore the chemistry of oxygen and combustion.

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.

Just Breathe: The Oxygen Content of Air

In this Activity, students determine the concentration (percent volume) of oxygen in air. They place small quantities of fine steel wool into a test tube that is then inverted in a beaker of water. Oxygen in the trapped air reacts with the iron to form rust. The Activity ties in well with atmospheric chemistry.

Boyle's Law: J-Tube

The relationship between the volume of a gas and the pressure it exerts, known as Boyle's Law, is shown with a J-tube.