Chemical Mystery #9: Liquid Nitrogen vs. Dry Ice

Bucket launch

A favorite experiment of mine is the bucket launch. My students and I recently tried two variations on this experiment. Watch the video below and see if you can explain the differences we observed.

Consistently, the one method always worked better than the other. Why do you think this is so?

If you know your chemistry you can figure this out!

The solution can be found here.

HAZARDS:  I describe here some useful tips if you plan on trying this experiment yourself. Please know that all details required for a safe and successful launch have NOT been described herein.  If you try this experiment, you do so at your own risk. The bucket needs to be liberally reinforced with duct tape.  Otherwise, the impact from the explosion will not launch the bucket in the air. Rather, the bucket will shatter into many pieces. After tightly sealing the bottle, STAND BACK.  Pieces of plastic from the exploded 2 L bottle can be thrown as far as 30 m. If the bottle is not sealed properly, hissing noises can be heard as gas escapes from the bottle.  In the event the bottle is not sealed properly, DO NOT approach the assembly until you are certain that all of the gas has escaped.



Safety: Video Demonstration

Demonstration videos presented here are not meant as tools to teach chemical demonstration techniques. They are meant as a tool for classroom use. The demonstrations may present safety hazards or show phenomena that are difficult for an entire class to observe in a live demonstration.

Those performing the demonstrations shown in this video have been trained and adhere to best safety practices.

Anyone thinking about performing a chemistry demonstration should first read and then adhere to the ACS Safety Guidelines for Chemical Demonstrations (2016) These guidelines are also available at ChemEd X.

General Safety

For Laboratory Work: Please refer to the ACS Guidelines for Chemical Laboratory Safety in Secondary Schools (2016).  

For Demonstrations: Please refer to the ACS Division of Chemical Education Safety Guidelines for Chemical Demonstrations.

Other Safety resources

RAMP: Recognize hazards; Assess the risks of hazards; Minimize the risks of hazards; Prepare for emergencies