Temp at which H20 will freeze
This question is kinda strange. I know that water will
freeze at 32F, but running water, on the other hand, seems
to run without freezing at a much lower temp. Also, some
water, like the spring water on my farm, even though there's
a little spot where it becomes a small pond seems to freeze at
a much lower temp. The other morning, when it was 25F all
water that was hanging around (with all the rain) was frozen
solid, but this little pond was unphased. Also, in the past
winters, when temps dip to the low teens, this pond still is
unphased. Its this because of the ground water temp
that is warmer than the outside temp, or maybe minerals in
the water that make the freezing temp below 32F??? If anyone has any ideas, please share them. thnx
Shawn
Re: Temp at which H20 will freeze
Moving water still freezes at 32 degrees but if the molecules are moving around they are generating heat. If the air temp is 32 the water still may not be 32 or freezing. The pond is a little different in that the depth will effect when its surface reaches freezing temperature. The deeper the lake or pond the longer it will take to freeze. Also the spring is constantly pushing water into that little pond that is warmer than 32 degrees that is why it will not freeze. There is a spring not far from me in New York State that flows all winter.
Re: Temp at which H20 will freeze
My father told me a story about a man back in the 'good old days' that thought that since the water out in the middle of a certain lake never froze; it would be suitable to put in the radiator of his car in the winter time!! Guess what the man learned the hard way!!! [img]/forums/images/icons/confused.gif[/img] [img]/forums/images/icons/confused.gif[/img] Needless to say, he found that anti-freeze was cheaper!!! [img]/forums/images/icons/laugh.gif[/img] [img]/forums/images/icons/smirk.gif[/img]
Re: Temp at which H20 will freeze
As I recall, the 32 degree freezing point for water is at sea level. Above or below sea level changes that number.
Re: Temp at which H20 will freeze
<font color="purple"> 32 degree freezing point for water is at sea level </font color>
Now we're really stretching to recall that high school science [img]/forums/images/icons/smile.gif[/img] Isn't there some stipulation in there about a certain barometric pressure, too? Raise or lower the pressure, and the freezing/boiling points change.
Re: Temp at which H20 will freeze
There is a Thermodynamics chart called a phase diagram that shows the relationship of temperature and pressure to the phase of a substance... solid, liquid or gas. There is a particular combination of temperature and pressure that water will occur at all three phases. This is called the triple point. The same chart explains why water boils at a different temperature at altitude and why you see different cooking instructions for high altitude conditions [img]/forums/images/icons/smile.gif[/img]
Re: Temp at which H20 will freeze
Here are some real esoteric links for those really interested in some technical reading:
What is 'unfreezable water'?
Freezing Water Myth
Physics of Freezing
Theoretical Aspects of the Freezing Process
Enjoy! [img]/forums/images/icons/grin.gif[/img]
Frank
Re: Temp at which H20 will freeze
<font color="blue">Raise or lower the pressure, and the freezing/boiling points change</font color>
That sounds right, since you can boil water by placing it in a vacuum without applying heat.
Re: Temp at which H20 will freeze
After taking years of meteorology classes one of the few things I can remember is that water does not have to freeeze until 40 below. This is called super cooled water and can be commonly found in cirrius clouds. One of the conditions for this water is purity.
A neat test of this is to wait one morning when the temperature is 40 below or colder (not counting windchill mind you) and get a glass of water and toss the water into the air. Before the water hits the ground you will hear a faint crack sound. Thats the sound of the water turning into ice.
Re: Temp at which H20 will freeze
Neat! I'll be sure and try that the next time it gets that cold here in Texas [img]/forums/images/icons/tongue.gif[/img]