does air pressure affect water freezing temperatures?

Answer 1

Yes, an increase in air pressure lowers the freezing point.

Answer 2

Indeed it does. Here are some fun facts about water. Most liquids freeze at a higher temperature under pressure, because the pressure helps to hold the molecules together. However, the strong hydrogen bonds in water make it different: water freezes at a temperature below 0 °C under a pressure higher than 1 atmosphere. Consequently, water also remains frozen at a temperature above 0 °C under a pressure lower than 1 atmosphere. The melting of ice under high pressures is thought to contribute to the movement of glaciers. Ice formed at high pressure has a different crystal structure and density to ordinary ice. Ice, water, and water vapor can coexist at the triple point, which is exactly 273.16 Kelvin at a pressure of 611.73 Pascal. Ice is the only known non-metallic substance to expand when it freezes.

Answer 3

Yes. If you take a block of ice and then subject it to high atmospheric pressure, you'll compress it to the point where the crytal structure breaks down, and it will turn into a liquid. This means, the higher the air pressure, the colder you have to get the water in order to make it freeze. (But it's a small effect compared to the effect of pressure on BOILING temperature).

Look up "water phase diagram" in Google (or just look here: http://images.encarta.msn.com/xrefmedia/aencmed/targets/illus/cha/T073590A.gif ), and you'll see a nice graph of temperature vs. pressure, divided into three distinct regions (solid, liquid and gas). This kind of diagram is neat for seeing at a glance how the phase of water depends on both temperature and on pressure.

Answer 4

Yes.

It also affects the boiling point. Pressure caps are used in car radiators to increase the boiling point, each PSI increase the boiling point by about 3 degrees F. So if you have a 15 PSI radiator cap, the temp would have to reach at least 267 degrees F Before it boils.

This is why when you remove the cap, it boils over all of a sudden with a dangerous spurt of steam. Even if it is at only 213 degrees, it will boil immediately upon releasing the pressure.

Answer 5

Yes, Presseure dictates the movement of molecules and since frozen state of water is simply a lack of movement for water molecules, pressure does play a part in determining the freezing point for water.

Answer 6

Yes, it has a slight depression on the freezing point when pressure increases.

Answer 7

only a very very small affect, due to the change of volume of water freezing to ice

Answer 8

yes