What would you like to ask?How does more or less air pressure affect the freezing point of water?

Question

I know if you add more air pressure to water, the boiling point rises...does more air pressure increase the freezing point to or does it stay the same?

Answer 1

wikipedia:

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 atm. Consequently, water also remains frozen at a temperature above 0 °C under a pressure lower than 1 atm. 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 vapour can coexist at the triple point, which is exactly 273.16 K (by definition) at a pressure of 611.73 Pa.

There are some 15 different forms of ice. see

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

Answer 2

If you try to boil water high up in the mountains, you find it boils easier, because the ambient pressure is lower. Boiling occurs when the vapor pressure is equal to the ambient pressure.