Sudden Phase change of water to ice

Click For Summary

Discussion Overview

The discussion centers around the phenomenon of sudden phase change of water to ice, particularly in the context of experiences with bottled water in cold environments. Participants explore the mechanisms behind nucleation and the effects of pressure and agitation on this process.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant describes an experience where water in a sealed bottle rapidly transitioned to slushy ice upon opening, suggesting a role for nucleation and questioning the impact of pressure on this process.
  • Another participant supports the idea of nucleation, noting that rapid changes in pressure can trigger nucleation events.
  • A different viewpoint suggests that while pressure changes may assist in nucleation, the pressure in the bottle is not significant enough to substantially alter the freezing point of water.
  • One participant draws a parallel to reusable heating packs, where a physical shock induces freezing, emphasizing the role of nucleation in both scenarios.
  • Another participant clarifies that the process in heating packs involves crystallization of salt rather than freezing, but agrees that nucleation is central to both effects.

Areas of Agreement / Disagreement

Participants generally agree that nucleation is a key factor in the phase change observed, but there is no consensus on the extent to which pressure influences this process or the specific mechanisms involved.

Contextual Notes

Participants express uncertainty regarding the precise relationship between pressure changes and nucleation, as well as the conditions under which these phenomena occur. The discussion does not resolve these uncertainties.

Who May Find This Useful

This discussion may be of interest to individuals exploring the physics of phase changes, nucleation processes, and related experimental phenomena in cold environments.

Whatson II
Messages
1
Reaction score
0
"Sudden" Phase change of water to ice

Last winter, I had a store-bought bottle of water I took snow camping. The closed bottle of water sat in the snow overnight. The next morning the water was still liquid, when I opened the bottle, I heard the hiss from the release of pressure on the bottle and, it "flashed" to a slushy ice almost instantly. At the time I figured it was an issue with the air pressure in the bottle (we were camping in the mountains) and a neat example of nucleation. Fast forward to this winter, I had two store-bought water bottles sitting in the car over night (this time, at home in the valley). The outside temperature was in the high teens to low 20's. Both of the bottles were closed, but of these two bottles, one was partially full and the other was completely full, and had not been opened yet. Both bottles of water were still liquid and laying on the car seat next to me. When I opened the partially full bottle, it flashed to ice just like the bottle last year. I was amused but not surprised. I was curious about the second bottle, I picked it up and, without opening it, it too flashed to a slushy ice right there in my hand, no opening or change in pressure involved. This did surprise me and gave me cause to question my assumption of the affect of pressure (or sudden change thereof) on the phase change from liquid to solid.
Is this a simple matter of two different causes (delta P and agitation) of nucleation?
Does the pressure in the bottle have any impact on nucleation?
If so, would it matter if the bottle were under vacuum or pressurized? That is, is it just the change in pressure that initiates the nucleation?
Would someone please elaborate on the physics involved with my experiences such that I could explain things further to my young son?

Thanks.
 
Physics news on Phys.org


I'm voting for nucleation- although fast changes in pressure can set off nucleation events.



Note- you can do a similar experiment (superheating) in the microwave. Be *very* careful.

 
Last edited by a moderator:
  • Like
Likes   Reactions: Limebat


My bet would be nucleation as well. Pressure in the bottle is not very high, so it won't substantially change freezing point. Could be sudden change in pressure helps in nucleation, but I doubt it is different from just shaking the bottle.

--
 


Same effect in these reusable heating packs, you have a liquid salt solution and click a little metal 'popper' in them - the shock makes the liquid freeze giving off heat.

http://en.wikipedia.org/wiki/Heating_pad
 


It is not freezing, it is crystalization of the salt - but you are right that it is simillar effect; in both cases it is all about the nucleation.

--
methods
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 18 ·
Replies
18
Views
11K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 8 ·
Replies
8
Views
1K
  • · Replies 21 ·
Replies
21
Views
3K
  • · Replies 32 ·
2
Replies
32
Views
12K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 4 ·
Replies
4
Views
5K
  • · Replies 4 ·
Replies
4
Views
2K