Question about the structure of ice

Originally posted by FabianFnas
We try with one molecule of water. Is this ice? No, we can all agree that there is no meaning talking about one molecule of ice.

The fun starts when we try two molecules of water to see if it can be considered as ice.

How do we attach the two molecules together?
Where do we have them to begin with? In some ind of vacuum not to be disturbed by othe really interesting. It' will be a future topic to discuss over a beer with some good friends.

I use DI water in our cleanroom, we have a facility that makes DI water from street water, a very large system of filters, Reverse Osmosis pumped filters and active ionization filters, the ultimate restistance of DI (De-ionized water) is about 18 megohms/sq. Cm, the standard measure for DI water.
That is water that has extremely little in it besides H20, no H+, O+, or much of anything else besides H20. So you have these mickey mouse ear shaped molecules, polarized because of the angle of the dangle and then as it starts to freeze, they must somehow pop out a bit to lower its density so ice can float. So I am thinking there has to be enough molecules in a 3 dimensional grouping for this state to appear. How many though, I don't know. I would bet money on it being a lot smaller a number of molecules than the 10^6 mentioned.
Found this article online from 1999 about the subject of the structure of ice, very informative, it says, among many other things, that there were 10,000 scientific papers written about ice in that year alone. So it's a big subject for sure. However it did not address my question of the minimum amount of water molecules needed for it to be called ice.
http://www.tms.org/pubs/journals/JOM/9902/Schulson-9902.html

Originally posted by sonhouse
That is water that has extremely little in it besides H20, no H+, O+, or much of anything else besides H20.

I didn't mention anything about O+. I said that water always is a blend of H2O, and a fraction of H+ and OH-. It sometimes happen that H2O brakes up and reconstructed back into H2O. This has nothing to do with purity. That's how water behaves. Quite natural.

one molecule of ice?

Every heard of the Zen question? What is the sound of one hand clapping?

🙂

Originally posted by sonhouse
I use DI water in our cleanroom, we have a facility that makes DI water from street water, a very large system of filters, Reverse Osmosis pumped filters and active ionization filters, the ultimate restistance of DI (De-ionized water) is about 18 megohms/sq. Cm, the standard measure for DI water.
That is water that has extremely little in it besides H20, n ...[text shortened]... needed for it to be called ice.
http://www.tms.org/pubs/journals/JOM/9902/Schulson-9902.html

How can you distil the H+ (shouldnt that be H3O+ ??) and OH- out of water? Isnt that a natural phenomenon?

Originally posted by FabianFnas
We try with one molecule of water. Is this ice? No, we can all agree that there is no meaning talking about one molecule of ice.

The fun starts when we try two molecules of water to see if it can be considered as ice.

How do we attach the two molecules together?
Where do we have them to begin with? In some ind of vacuum not to be disturbed by othe ...[text shortened]... really interesting. It' will be a future topic to discuss over a beer with some good friends.

"Water should be scripted H2O, H+, and OH- mixed. This means that a water molecule may be splitted in two ions"

Fabian- I know that is true in the liquid state but is it true as a gas (how?!?!) or a solid (possible I guess .. does ice consist partially of ionised lattice such as salt?? ) and as my previous post doesnt the +ve ions in water actually consist of H3O+ ions?

Originally posted by wolfgang59
"Water should be scripted H2O, H+, and OH- mixed. This means that a water molecule may be splitted in two ions"

Fabian- I know that is true in the liquid state but is it true as a gas (how?!?!) or a solid (possible I guess .. does ice consist partially of ionised lattice such as salt?? ) and as my previous post doesnt the +ve ions in water actually consist of H3O+ ions?

The piece I posted mentions a salt-water ice that can be up to 7.5% NaCl. The piece says there are something like 10 or more kinds of ice.
One very recent article tells of the existance of water ice at 108 degrees farenheight in a nanometer thick layer associated with a nanocoating of diamond said to maybe be useful for artificial hip implants where the ice layer smooths out the submicroscopic defects of the diamond layer which may make for a longer lived implant. I'll try to rustle up the article. Found it:
http://www.sciencedaily.com/releases/2007/09/070905203345.htm

Originally posted by sonhouse
The piece I posted mentions a salt-water ice that can be up to 7.5% NaCl. The piece says there are something like 10 or more kinds of ice.
One very recent article tells of the existance of water ice at 108 degrees farenheight in a nanometer thick layer associated with a nanocoating of diamond said to maybe be useful for artificial hip implants where the ic ...[text shortened]... rustle up the article. Found it:
http://www.sciencedaily.com/releases/2007/09/070905203345.htm

Have we changed subject? I thought we were discussing the original problem of yours. Sorry.

Originally posted by FabianFnas
Have we changed subject? I thought we were discussing the original problem of yours. Sorry.

basically in response to wolfgang who asked about the structure of brine ice.

Originally posted by sonhouse
basically in response to wolfgang who asked about the structure of brine ice.

Sirry if I mislead anyone. I was thinking about pure ice. The salt connection was just abad analogy.

😳

A new phenomena has just been observed, here is the article:
If two beakers with water in them are exposed to a high voltage electric field, the water molecules climb up the side of the beakers and come together in a water bridge up to 25 mm long! This is brand new science, you read it first here folks! Nothing to do with ice but it is startling behavior nonetheless!
http://www.physorg.com/news110191847.html

Thanks for that link! Good to know that water is still a mystery!

And while its still a mystery I wont risk it .. I'm sticking to good old C2H5OH

😵

Originally posted by wolfgang59
And while its still a mystery I wont risk it .. I'm sticking to good old C2H5OH

I'd second that.

(And I'm sitting next to an empty bottle of red wine that would agree with me)

Originally posted by mtthw
I'd second that.

(And I'm sitting next to an empty bottle of red wine that would agree with me)

In Vino Veritas. Pliney the younger.

http://www.lsbu.ac.uk/water/ice1h.html

Generally going by the minimal unit cell should be sufficient. At the very bottom of this page, marked c it gives the unit cell of ice as containing 4 molecules of water. The question of water spontaneously ionising into H+ and OH- is a temperature dependant property and the proportion of ions to covalently bonded molecules reduces with temperature. For the purposes of defining the crystal structure, 4 molecules is enough to be sure you have ice. Any less and you can't be sure that you have a unit cell. any more in the required structure simply increases the amount of ice you have, but I think the original question was what the minimum was. (4)

I booked that site. The first image there shows 12 molecules. Isn't that the minimum? How can it have the hex pattern with less than 12?