Freeze water at room temp?

[stack_climbe]

Certain concentrations of Brine become solid at temperatures above 32 deg F.

 

Is there a way to know the exact ratio of water to salt?

[Darkblade48]

As far as I knew, the addition of salt depresses the freezing point (i.e. salt water will not freeze at 0 C).

[stack_climbe]

There is actually a curve where the freezing point rises above 0 C then drops again. Don't know what the curve is just know that it is. There is a facility in my area that pumps brine from the oil fields then extracts bromine from the brine. The brine is heated in order to keep it fluid enough to pump long distances.

[DrDNA]

Do you know the pressure of the brine in the line or in the pump? This would effect the point at which it turns to solid.

I don't think it will happen at atmospheric pressure.

 

Heating also lowers the viscosity of the fluid to make it easier to push through the lines.

[John Cuthber]

When you say "There is actually a curve where the freezing point rises above 0 C then drops again. " do you realise that's a departure from the normal laws of physics?

Are you getting confused with the fact that if you cool a solution of salt down then salt might come out of solution, rather than ice?

 

Here's a nice page with a phase diagram.

http://www.chemguide.co.uk/physical/phaseeqia/saltsoln.html

 

The fact that they heat the brine to make it easier to pump isn't relevant.

[stack_climbe]

So by the phase diagram I understand that with salt concentration of >23.3% solids will begin to form at increasing temperatures but the solids are actually salt crystals not ice. Makes sense. I'm sure this is what I was thinking of but it would seem that heating the high salt concentrations such as with the brine pipelines would actually make the slolution less fluid not more.

[Darkblade48]

So by the phase diagram I understand that with salt concentration of >23.3% solids will begin to form at increasing temperatures but the solids are actually salt crystals not ice. /QUOTE]

 

What? At a salt concentration of > 23.3 %, at a temperature below -21.1 Celsius, you will have salt that has precipitated out, and frozen water. At a higher temperature (i.e. less negative), you will have solid salt (i.e. it has precipitated out) and (salt) water.

[Riogho]

CaCl formula units will get between the water molecules and and calcium will usually squeeze itself near the oxygen (partial charges attract), and make it hard for the water to set up a rigid structure, thus lowering it's freezing point.

 

Or so I've been told

[thedarkshade]

You mean [ce]CaCl2[/ce] Riogho!

 

edit: sorry for posting in an oldish thread!

[Fuzzwood]

Not possible as water has a negative solid liquid line

[Mr.Chockuls]

i made some NaSO4 but i didn't filter it, so wather was there, and in lap of the next day it was like crystal.