Question:
What are the properties of a supercooled liquid?
anonymous
2007-09-18 10:40:19 UTC
Could someone please tell me what the properties of a supercooled liquid are becuase I have searchef everywhere and can't find anything. Thankyou x
Three answers:
anonymous
2007-09-18 11:04:07 UTC
They are liquids that have been cooled below their normal freezing point. To do this you have to be very careful to ensure that there are no 'nucleation points' like microscopic air bubbles in them or dust particles or sharp points / scratches in the container wall.



Liquids release a lot of heat when they freeze so the liquid really needs to be well below freezing temperature when you do finally introduce some nucleation points or not very much of the (warmer) solid is formed.
Rhonnie
2007-09-18 17:52:25 UTC
Supercooling is the process of chilling a liquid below its freezing point, without it becoming solid.



A liquid below its freezing point will crystallize in the presence of a seed crystal or nucleus around which a crystal structure can form. However, lacking any such nucleus, the liquid phase can be maintained all the way down to the temperature at which crystal homogeneous nucleation occurs. The homogeneous nucleation can occur above the glass transition where the system is an amorphous—that is, non-crystalline—solid.



Water has a melting point of 273.15 K (0 °C or 32 °F) but can be supercooled at standard pressure down to its crystal homogeneous nucleation at almost 231 K (−42.15 °C).[1] If cooled at a rate on the order of 106 K/s, the crystal nucleation can be avoided and water becomes a glass. Its glass transition temperature is much colder and harder to determine, but studies estimate it at about 165 K (−108.15 °C).[2] Glassy water can be heated up to approximately 150 K (−123.15 °C).[1] In the range of temperatures between 231 K (−42.15 °C) and 150 K (−123.15 °C) experiments find only crystal ice.



Droplets of supercooled water often exist in stratiform and cumulus clouds. They form into ice when they are struck by the wings of passing airplanes and abruptly crystallize. (This causes problems with lift, so aircraft that are expected to fly in such conditions are equipped with a deicing system.) Freezing rain is also caused by supercooled droplets.



An equivalent to supercooling for the process of melting solids is much more difficult, and a solid will almost always melt at the same temperature for a given pressure. It is, however, possible to superheat a liquid above its boiling point without it becoming gaseous.



I hope it helps!
Alexander
2007-09-18 17:47:19 UTC
You cannot find anything, because there's nothing special about supercooled liquids. They do not have any special properties.



They are meta-stable - it's the only property that distinguishes them from normal liquid.


This content was originally posted on Y! Answers, a Q&A website that shut down in 2021.
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