Quote:
Originally Posted by RCAlyra2004
We also have similar problem with fresh water forming ice deep underwater on the structures of our power stations. Because the water moves so quickly through the river it can become super cooled without freezing.
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I don't think "moving fast" is a condition that allows supercooling. Agitation is normally a condition that causes nucleation and propagation of phase change. I would be interested to know why this phenomena occurs, though.
Also, supercooling normally does not occur, even in a "clean" water supply. I'm not questioning the added energy requirement necessary to overcome the surface tension which occurs when a particle of a different phase is created, it's just that ordinary water (yes, even distilled water) is normally not that clean. There is already particluate in it which acts as a nucleation center and greatly reduces the surface tension of the new phase. Water that is actually clean is called nanopure water, and we buy it to make buffers which will be used in chemical detection instruments.
The jug thing baffles me. The entire contents turned to ice? The enthalpy of fusion of ice is 334 joules per mL (or gram). This is 80 calories. Even assuming that 1/4 of the jug froze and this was enough to break it, that would still mean that the water was at -20*C.
...Oh, and don't think it's not cold here. I'll wake up and it'll be -25*C (-13*F) here, so it's not like I don't know cold.