Liquid Nitrogen Bottle Rocket Experiment

CAUTION! Do not try this at home. This experiment uses liquid nitrogen which is EXTREMELY cold. Safety precautions were taken in the filming of this video.
Many know that liquid nitrogen is extremely cold, at -321ºF.  When it is exposed to extreme temperature differences, you can observe something called the Leidenfrost Effect. To learn more about the Leidenfrost Effect click here. Once the insulating barrier from the Leidenfrost Effect goes away, then the liquid nitrogen will boil.

Due to the liquid nitrogen boiling, it will produce a lot of gas. Gaseous nitrogen has a lot more energy than liquid nitrogen resulting in a rapid expansion and pressurizing of the gas. While the bottle is right side up, the gas can easily expand and escape the bottle through the nozzle.  However, when flipped upside down, the gas has nowhere to expand to which pressurizes the bottle, forcing the water down and out of the bottle.

Newton’s’ Third Law says that for every action there is an equal and opposite reaction.  The water being forced to travel downward results in sending the bottle skyrocketing upwards! How high do you think this rocket launched?