Water expands?

Why does water expand? That don't make sense to me. I understand from my science classes as a kid that moecules get closer togather as they get colder. So why would water expand and bust things which seems to bet the case in the winter like water pipes? Please give me a scientific answer for this whith a reply at [email protected].

Water is an intersting mysterious substance. That's all I have for you. It is most dense at 33 degrees Fahrenheit.

Freezing point
A simple but environmentally important and unusual property of water is that its common solid form, ice, floats on its liquid form. This solid phase is not as dense as liquid water because of the geometry of the hydrogen bonds which are formed only at lower temperatures. For almost all other substances the solid form has a greater density than the liquid form. Fresh water at standard atmospheric pressure is most dense at 3.98 °C, and will sink by convection as it cools to that temperature, and if it becomes colder it will rise instead. This reversal will cause deep water to remain warmer than shallower freezing water, so that ice in a body of water will form first at the surface and progress downward, while the majority of the water underneath will hold a constant 4 °C. This effectively insulates a lake floor from the cold. The freezing point of water is 0°C (32°F, 273 K).

WATER


I hope this helps a little!

If you look into the convection of water, this will help illustrate how "Global Warming" can cause an ice age on certain continents.

As water cools it contracts thus letting more water in the pipe until it freezes. Then as it starts to thaw it starts expanding again and as there is now more water in the pipe than can fit the pipe cracks to let the excess water out.

Hence the reason pipes crack in Winter - hope this helps.

When you raise the temperature of a liquid to its vapor point and add enough heat to vaporize it, it forms gaseous molecules of the substance. The gas expands assuming a constant pressure.

Water however undergoes a form of interaction between molecules known as hydrogen bonding. This occurs for O, N and F when bonded to H. These compounds have higher boiling points than similar compounds without hydrogen bonding.

Consider water, H20 and hydrogen sulfide, H2S. Sulfur is below oxygen and hydrogen sulfide has a higher molecular weight than water which should correspond to a higher boiling point. This is not the case however, water's boiling point is almost 160 degrees C higher.

Or take the example of hydrogen fluoride and hydrogen chloride. The is no hydrogen bonding for hydrogen chloride as there is for hydrogen fluoride. Now take into account hydrogen bromide which has a higher weight than hydrogen chloride and a higher boiling point, and of course has a higher weight than hydrogen fluoride but yet its boiling point is lower than hydrogen fluoride. That is hydrogen bonding.

[edit on 20-2-2007 by etotheitheta]