Which Water Supercools Best?

Most recent answer: 01/14/2017

Q:
Supercooled Water ContinuedFrom your answers I gathered a few assumptions and I wanted to know if they are correct. 1) Distilled water would be easier to supercool, 2) Still water is easier to super cool.I ask because there is a video on YouTube about Aquafina water not freezing while all other water and water bottles were frozen. Could this relate specifically to the particle content in the water? I also wanted to ask about the release of heat when water freezes, could this effect freezing of water when the temp is not too cold and the space is enclosed.
- Jessica (age 29)
Thedford, Ontario, Canada
A:

Distilling removes molecular impurities in water, but the key nucleation sites to trigger ice forming are bigger particles, like little pieces of dust or bubbles. Flowing water is likely to have bubbles that trigger freezing, for the same reason that you can often trigger freezing in a supercooled bottle of water by shaking it.

Some bottled waters are filtered in ways that remove particles, so those are the easiest ones to supercool.

The release of heat when water freezes is very important in determining what happens to supercooled water. You can't supercool water enough for it all to freeze solid, because the released heat will warm it up to 0°C after part of it has frozen. That's why you get slush.

We discuss more here: https://van.physics.illinois.edu/qa/listing.php?id=1618.

Mike W.


(published on 01/14/2017)