Why did this happen? (science question)

[CardSharpCook]

So my roommate buys these two thai energy drinks and brings them home. They are warm. We put them in the freezer to make them cold. After waiting some amount of time, we remove the drinks from the freezer. They are still liquid. No ice has formed. He advises that I shake the drink. I do so and immediately the entire drink turns into an icey slush. I can't explain why this would happen. Can you?

[Neuge]

There probably weren't any nucleation sites for the ice crystals to start forming. The aeration caused by shaking would provide some. Everyone knows water freezes at 0C, what most people don't know is that water freezes at -41C in the absence of nucleation sites.

[jman3232]

In a physics or chemistry class (I dont remember which) a teacher mixed salt with water and you can cool it past the freezing point. (or heat it past the booling point, i really dont remember). When you shake it, it makes the substance unstable and then go back where it "should be"

[vhawk01]

[ QUOTE ]
In a physics or chemistry class (I dont remember which) a teacher mixed salt with water and you can cool it past the freezing point. (or heat it past the booling point, i really dont remember). When you shake it, it makes the substance unstable and then go back where it "should be"

[/ QUOTE ]

Colligative properties FTW

[alphatmw]

theres a youtube video of this happening to a beer.

[surftheiop]

supercooling?
http://en.wikipedia.org/wiki/Supercooling

[jman3232]

oh yeah that was it I think. if you very slowly cool the liquid it is able to cool past its freezing point for some reason. If you cool it too fast or disturb it by shaking it then it turns into ice.

[CORed]

[ QUOTE ]
supercooling?
http://en.wikipedia.org/wiki/Supercooling

[/ QUOTE ]

Supercooling is quite imprtant in weather. Supercooled water droplets commonly occur in clouds, and sometimes fog. When you have supercooled fog, you get rime ice formation on trees and bushes. Freezing rain and freezing drizzle occur when super-cooled rain drops fall, and rapidly freeze when they hit the ground, roads, trees or power lines.

Precipitation happens largely because some, but not all, of the droplets in supercooled clouds nucleate on dust particles. Because ice is a lower energy state than super-cooled water, the vapor pressure over water is higher than that over ice, so the ice crYstals grow (and become snowflakes) at the expense of the super-cooled water droplets, eventuaolly becoming heavy enough to fall out of the cloud. A lot of rain starts as snow, and melts as it falls into warmer air at lower altitudes.

Cloud seeding attempts to increase precipitation by providing more particles (usually very small silver iodide particles) for nucleation.

[Prodigy54321]

this happened to a gatorade I put in the freezer once

[CardSharpCook]

thanks guys [img]/images/graemlins/smile.gif[/img]