system
Given the following post, respond as if you're commenting on Reddit:
human
How can freezing water break matter?

I'm not sure how to put it exactly so here is a simple, "ideal" scenario:

If I put a bottle of water in a room and start removing heat from the room, the water will first lose its sensible heat until it gets to 0 C.

Then, the water will give up its latent heat and start freezing. Since ice is less dense than liquid water, it will start to expend in volume as well.

But if my bottle is closed, the ice will build pressure inside it until it breaks. The ice will do "work" on the bottle.

My question is: how could the formation of ice break the bottle if the water is already giving up energy as heat? Is there a force known as "work energy of crystal formation" that would explain it? How could it be explained on an atomic level?

Thank you for considering this. I couldn't find a satisfying answer by myself.
gpt
Phase transition "water -> ice" produces heat, but it doesn't mean that it *has* to produce heat. Unless heat is actually taken away from the water, it will not freeze. Unlike, say, a radioisotope source which constantly produces heat as a result of radioactive decay of its fuel, and will just heat itself up if left fully insulated; a bucket of water in the process of freezing will not heat itself up though.

Freezing happens because as you continue to take energy away from liquid water around 0°C, its molecules can collectively occupy lower energy states by becoming a part of crystal lattice. The phase transition can only happen if this extra energy will dissipate, usually through thermal contact. However, there's nothing that prevents you from using the energy to do work instead! Stretching the bottle and heating the freezer around the water bottle are not two independent processes, they use the same energy released in the process of crystallization.