Spinning Jet Stream

In this demo a ping pong ball with a hole along the seam is submerged in liquid nitrogen (-196⁰C) to fill it. When removed, the nitrogen in the ball boils and is forced out of the hole in a stream. The stream, which comes out at an angle, causes the ball to spin away from the stream. The “stream” that we see is condensed water vapor, not nitrogen gas.

Pressure Cooker

boiling water in a low pressure syringe

In this demonstration, warm water is placed in a plastic syringe, the syringe is sealed, and the plunger is pulled back causing the water to boil. The water boils because the action of pulling back the plunger increases the volume, thus decreasing the pressure. The boiling point of a liquid is dependent on the pressure of the system, so a decrease in pressure leads to a decrease in boiling point.

Liquid Nitrogen Ice Cream

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Liquid nitrogen is -196˚C and quickly freezes the ingredients into ice cream. The nitrogen boils out leaving deliciously creamy ice cream. The “fog” that we see is condensed water vapor though, not nitrogen gas.

Shrink A Balloon

shrink a balloon liquid nitrogen

When a balloon is placed in liquid nitrogen the air inside it is condensed from the cold (-196°C), causing the balloon to shrink. Once the balloon is removed it will regain its size as the air heats up. Liquid nitrogen boils at room temperature. The “fog” that we see is condensed water vapor though, not nitrogen gas.

Shatter a Flower

When a flower is dipped in liquid nitrogen (-196°C) it is instantly frozen. Liquid nitrogen boils at room temperature. The “fog” that we see is condensed water vapor though, not nitrogen gas.

Relight A Candle

Candle wax is flammable as a vapor, so a candle can be relit by igniting the smoke trail of a recently blown out candle, which contains wax vapor. This can be used to demonstrate how caution needs to be taken with flammable vapors.

Mushroom Cloud

dry ice mushroom cloud bubble

When dry ice is placed in warm water it sublimes very quickly forming a large amount of carbon dioxide gas. When a bubble is placed over this the bubble grows from the pressure.

Dry Ice in Universal Indicator

dry ice universal indicator acid base reaction

Universal indicator goes from red (pH 4) to violet (pH10) as the pH of a substance changes. Adding NaOH to water starts the solution off at pH 8-9 (blue). When dry ice is added to water it forms carbonic acid, and lowers the pH, which is the reason for the color changes. The “fog” that we see is condensed water vapor though, not carbon dioxide gas.

CO2 Bubbles

dry ice soap bubbles

CO2 gas from subliming dry ice gets caught in a soapy solution creating a column of bubbles. When the bubbles are popped, the “fog” that we see is condensed water vapor, not carbon dioxide gas.

Camphor Particles

camphor sublimation

In this demo, camphor particles are placed in water. They sublime at room temperature which is why camphor’s odor permeates the room so quickly. The gas that forms around the particles propels the particles in random directions. Earwax contains a large percentage of long chain fatty acids which form a monolayer in water, thus ceasing the motion of the camphor particles.