Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: chris on 31/01/2023 11:58:52

Title: Will water at low pressure still freeze at zero degrees?
Post by: chris on 31/01/2023 11:58:52

Water under a lower pressure boils at a lower temperature because the lower pressure makes it easier for molecules to gain sufficient energy from the liquid to sever the intermolecular forces within the fluid and escape as a vapour. But what happens to the freezing point?

Title: Re: Will water at low pressure still freeze at zero degrees?
Post by: Bored chemist on 31/01/2023 12:55:48

At a reduced pressure the freezing point rises slightly. (At most, roughly 0.01 degrees C)
For most materials (those which contract on freezing) the freezing point would reduce .

It's an example of this
https://en.wikipedia.org/wiki/Le_Chatelier%27s_principle

Title: Re: Will water at low pressure still freeze at zero degrees?
Post by: vhfpmr on 31/01/2023 13:03:05

https://naeye.net/wp-content/uploads/2021/01/water_phase_diagram.jpg

Title: Re: Will water at low pressure still freeze at zero degrees?
Post by: chris on 02/02/2023 17:08:53

Dare I ask why this phenomenon occurs?

Title: Re: Will water at low pressure still freeze at zero degrees?
Post by: Bored chemist on 02/02/2023 18:28:10

Quote from: chris on 02/02/2023 17:08:53

Dare I ask why this phenomenon occurs?

Apparently.
And to an extent the answer is

https://en.wikipedia.org/wiki/Le_Chatelier%27s_principle

Title: Re: Will water at low pressure still freeze at zero degrees?
Post by: alancalverd on 03/02/2023 09:24:11

Fun news item this morning. Apparently University College London have made (or discovered)  a disordered  state of ice by milling the regular stuff into a glassy solid with a density of 1.0.