Can We Freeze Water By Compressing It With A Hydraulic?

[Sachin114]

PV=nRT... So V is directly proportional to T. Can we compress and reduce the volume of water by means of a hydalic press and reduce its temparature to freezing point???

[Old_Geezer]

Interesting question. Pressure lowers the freezing point so possibly not, well unless the freezing point lowering drops more slowly than the rate that the pressure increases. I'm unsure what type of solid you'd get. Been too long since I was last in a science (or even a maths) class.

Give it a go and let me know how you get on.

[douglas9401]

No.

http://water.usgs.gov/edu/compressibility.html

[Calibax]

PV=nRT relates to gases. You can compress steam but you can't compress a liquid.

[Togo]

//Water is a pretty amazing substance. If you keep it at a constant temperature you can actually take ice and compress it and get liquid water! Application of further pressure it will solidify again, just do to the increased pressure! This solid however would not be the ice we are used to. The structure would be different do to all that pressure! Eventually if you kept increasing the pressure, the water would undergo fusion! Compress it further and it would form electron degenerate matter (like a white dwarf star), even further it would make neutron star material (so dense that the electrons are compressed into the protons and only neutrons remain!). Any farther and you’d get to a black hole!! That would take an astronomical (literally!) amount of pressure!!//

I found this online Sachin. It was posted in answer to a similar question in 2011. The answer was by Sara Imari Walker.

[Peter Pedant]

o dear where is the prof

a very technical point is: look at the phase diagram for water
the ice/liquid line has a negative slope
this means as you compress a system ( whether or not it is incompressible ) then the temperature of freezing goes down .....
so in that system you are still gonna have to remove heat

this answer is even more technical
https://www.reddit.com/r/askscience/comments/2nfeix/if_water_is_compressed_enough_would_it_turn_solid/

BUT BUT BUT
the idea is OK
the Brit Mus has a show on mughal jewellery featuring hard stone chased with gold - and THEY said that with a needle point, the gold was compressed into the fine crevasse in the hard stone and by reason of the above, would liquefy under the needle point - and so you could inlay / chase gold into a hard stone.

( well you could see that you could achieve that because the object is there to examine but that is how they said it was done )

some pretty spectaular examples here but not much inlay

[Hopkirk]

Oh Togo, and there was me thinking you were a highly qualified scientist.

[Old_Geezer]

From a quick Google it seems that there are different types of ice (seems to ring a bell with me but I'm unsure why) and so you get a different type of ice depending on the pressure. I'm unsure if one calls that "frozen" though.

[Togo]

Haha Hopkirk. I knew that the short answer was no, so I had a look online to try and form an answer. The one I posted was pretty succinct so I purloined it. I would though have changed do to, to, due to. (that's easy for you to say). (^_*)

[Peter Pedant]

PV = nRT is irrelevant for this
you shoul dbe looking at phase diagrams

[Khandro]

I think Leonardo da Vinci was the first to write that you cannot compress water. It was discussed on an AB science thread some years ago and the conclusion was, that to all intents and purposes, he was correct.

[Peter Pedant]

no we are talking about whether freezing point of water is dependent on ambient pressure and the answer to that is yes

it is still open ( where is prof ?) whether you can vary it enough to change state ( = freeze )

we know boiling point of water is dependent on pressure ( water boils at a lower temp up everest ) and the sameis true of freezing point

[Hypognosis]

Water is densest at 4°C so the formation of natural ice is preceded by convection, as the denser water settles to the bottom of the body of water in question, prior to the surface forming an ice sheet which floats because, almost uniquely, water ice is less dense than liquid water. The van der Waal's forces which make liquid phase molecules slip past one another form hydrogen bonds, instead and the dimensions of these bonds are larger than the typical spacing between molecules in the liquid state.

The incompressability is (I can't prove this) likely because, assuming random orientations of water molecules, enough are aligned with polarised oxygen facing another polarised oxygen (electrostatic repulsion forces) and pairs of polarised hydrogens facing pairs of polarised hydrogens (double dose of electrostatic repulsion).

Give or take the salt content, we know that ocean water remains liquid at the bottom of the Marianas trench (over 10,000m), representing pressures of tonnes per square centimetre. Even with extremely heavy-duty equipment, to all practical intents and purposes, you will not be able to generate such pressures at ground elevation.

Needle-tip pressure, as in Peter's example might amplify pressures to the scale required but then your exotic ice stucture will be no larger than the needle tip; a few atoms across.

[waterboatman]

You can't compress a liquid. That's how hydraulics work.

[Hypognosis]

Forcing ice to change to water, using pressure (the opposite of what you're asking for) is possible and makes for an intriguing demonstration, which youngsters will love, because it challenges their perceptions.



In this case, the liquid refreezes because the ice block draws away the heat which melted it. I say 'heat' but, of course, it is gravity, converted into pressure (small surface area of the wire) which physically crushes the hydrogen bonds until they break and the molecules liquify, so there is a transfer of energy required to break bonds.

[Hypognosis]

Hello Boaty.

You can't compress solids, either. ;-)

[Khandro]

Hypo; ^^ That depends on your definition of solid. Is wood solid?

[waterboatman]

Hiya hypo. how you doing? :o}

Actually, some solids can be compressed. Rubber being a good example. ;o}

[Sachin114]

Its right that Ideal Gas Law does not apply to liquds. This slipped from my mind while i was posting the question. But after reading the thread now i am intrigued by the question Peter has raised. Can there be an experiment to verify this?

[jim360]

The discussion on compression of water can be found here:

http://www.theanswerbank.co.uk/Science/Question1244236-2.html