Science Buddies: "Ask an Expert"

Hello,

Maybe its a stupid question, but I was wondering what would happen if you have a very hard and thick container (metal or something) with water trapped inside, then expose to very cold temperature, I guess the water wont be able to turn into ice and stay liquid but with temperature below 0 ?

Thanks

Hi trom,

Yes, you are correct. In your thought experiment the water is not allowed to expand when cooling below ~4ºC. This causes the pressure in your ideal container to increase and the freezing of water will be delayed.

Conversely, we can take water ice at 0ºC, compress it, and it will convert to liquid water.

An example of your idea is here: https://www.youtube.com/watch?v=C13BQvPaBjw

When he opens the cap, the pressure releases and the water freezes.

This behavior is captured in a "phase diagram" if you're interested to read more.

https://en.wikipedia.org/wiki/Phase_diagram

-John