User not logged in - login - register
Home Calendar Books School Tool Photo Gallery Message Boards Users Statistics Advertise Site Info
go to bottom | |
 Message Boards » » question about freezing temp/32 deg. at sea level Page [1]  
joerrad
All American
3075 Posts
user info
edit post

ok i have a strange question.

if water freezes at 32 degrees (@ sea level), what temp does water freeze at when it is above sea level or below sea level.

[Edited on December 27, 2005 at 10:06 PM. Reason : .]

12/27/2005 10:06:20 PM

9one9
All American
21497 Posts
user info
edit post

ahahahah

12/27/2005 10:06:51 PM

LiusClues
New Recruit
13824 Posts
user info
edit post

ahahahah

12/27/2005 10:08:21 PM

AttackLax
All American
2304 Posts
user info
edit post

above = -13 degrees
below = 57 degrees

12/27/2005 10:09:39 PM

2
Suspended
362 Posts
user info
edit post

ahahahah

12/27/2005 10:09:56 PM

CharlieEFH
All American
21806 Posts
user info
edit post

12/27/2005 10:27:56 PM

stowaway
All American
11770 Posts
user info
edit post

ahahahahahahahahahaha







http://www.csgnetwork.com/h2ofreezecalc.html

figure out the normal pressure at different altitudes and plug it in.

12/27/2005 10:31:34 PM

CharlieEFH
All American
21806 Posts
user info
edit post

Quote :
"For Automotive Calculators, Converters and Tables
For Aviation Calculators, Converters and Tables
For Communications Calculators, Converters and Tables
For Computer Calculators, Converters and Tables
For Electronics Calculators, Converters and Tables
For Business And Financial Calculators, Converters and Tables
For General Interest Calculators, Converters and Tables
For Geography Related Calculators, Converters and Tables
For Health Calculators, Converters and Tables
For Helpful Math Converters and Calculators
For Lottery Calculators, Converters and Tables
For Maintenance, Construction And Remodel Calculators, Converters and Tables
For Marine Calculators, Converters and Tables
For Pure Educational Math Converters and Calculators
For Science Calculators, Converters and Tables
For Small Game Simulator Calculators, Converters and Tables
For Sports Calculators, Converters and Tables
For Subroutines And Snippets Source Code For Converters and Calculators
For Time Calculators, Converters and Tables
For Weather Calculators, Converters and Tables
Co-operating Sponsors and Technology used on our Website"


12/27/2005 10:32:39 PM

2
Suspended
362 Posts
user info
edit post

^^umm ocean water doesn't freeze at the same temperature as regular water

12/27/2005 10:47:47 PM

stowaway
All American
11770 Posts
user info
edit post

you change the salinity to 0

12/27/2005 11:03:05 PM

Duff Man
All American
4627 Posts
user info
edit post

i think water freezes at 32 degrees. for every 1000 feet in altitude you go up, you lose 4 degree on average.

i know that when we are preparing to go flying, we have to watch the freezing layer, based on what the temp where the first signs of visible moisture (clouds) is.

this is just from my standpoint, could be completely wrong.

12/27/2005 11:03:19 PM

moron
All American
34142 Posts
user info
edit post



This chart explains it more clearly, I think.

[Edited on December 28, 2005 at 12:18 AM. Reason : ]

12/28/2005 12:17:45 AM

JH Price
All American
1571 Posts
user info
edit post

^ how does this answer the question?

12/28/2005 12:31:45 AM

CharlieEFH
All American
21806 Posts
user info
edit post

stick to computers buddy

12/28/2005 12:50:55 AM

JonHGuth
Suspended
39171 Posts
user info
edit post

i fail to see how that explains it more clearly than a temp-pressure diagram

12/28/2005 12:57:35 AM

Duff Man
All American
4627 Posts
user info
edit post

alot of meterolgical terms are based on standard day, which is sea level 29.92 barometric pressure.

12/28/2005 12:59:21 AM

schmitter5
All American
2169 Posts
user info
edit post

Lowest Point in the World (and Asia)
Dead Sea shore, Israel-Jordan: 1312 feet / 400 meters below sea level
(The pressure of the atmosphere here is known to be extremely high, enough to filter the sun's UV rays.)

Lowest Point in Africa
Lake Assal, Djibouti: 512 feet / 156 meters below sea level

Lowest Point in Australia
Lake Eyre: 52 feet / 12 meters below sea level

Lowest Point in Europe
Caspian Sea shore, Russia-Iran-Turkmenistan, Azerbaijan: 92 feet / 28 meters below sea level

Lowest Point in Western Europe
Tie! Lemmefjord, Denmark and Prins Alexander Polder, Netherlands: 23 feet / 7 meters below sea level

Lowest Point in North America
Death Valley, California: 282 feet / 86 meters below sea level

Lowest Point in South America
Bahia Blanca, Argentina: 138 feet / 42 meters below sea level


According to Wikipedia though the actual lowest point is:
The Bentley Subglacial Trench is a vast trench in Antarctica. At 2,538 meters below sea level, it is the lowest point on the surface of the earth not covered by ocean, although it is covered by ice. It is similar in size to the nation of Mexico.

The trench is named after Charles Bentley, a geophysicist who led many scientific expeditions in Antarctica.

12/28/2005 2:11:38 AM

moron
All American
34142 Posts
user info
edit post

^^^ I read the original question improperly is how.

12/28/2005 2:17:58 AM

goFigure
All American
1583 Posts
user info
edit post

I CAN"T TAKE THE PRESSURE

PVT... but I took chem 101 5 1/2 years ago so I don't remember shit

12/28/2005 2:25:59 AM

humandrive
All American
18286 Posts
user info
edit post

For all practical purposes, there is no change in the freezing point of water with a change in elevation. It's not at all like the boiling point.

12/28/2005 7:21:59 AM

Maverick
All American
11175 Posts
user info
edit post

Quote :
"i think water freezes at 32 degrees. for every 1000 feet in altitude you go up, you lose 4 degree on average.

i know that when we are preparing to go flying, we have to watch the freezing layer, based on what the temp where the first signs of visible moisture (clouds) is.

this is just from my standpoint, could be completely wrong.

"


To expand, Clay is referring to the standard standard lapse rate (Average decrease in temperature of approximately 2C or about 5F per 1000 ft). The freezing temperature should remain relatively constant.

So in practical terms, if the temperature at ground level is 10C, then you can expect ice at 5000 ft.

The freezing point will not change, however, the average temperature will, which will cause icing at higher altitudes.


[Edited on December 28, 2005 at 8:10 AM. Reason : .]

12/28/2005 8:04:22 AM

Arab13
Art Vandelay
45180 Posts
user info
edit post

lol that was a good one....

12/28/2005 4:27:16 PM

darkone
(\/) (;,,,;) (\/)
11610 Posts
user info
edit post



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

12/28/2005 10:22:53 PM

EhSteve
All American
7240 Posts
user info
edit post

According to my thermodynamics textbook and the first problem we had to do last semester (this is the prof's solution, so if you think it's wrong, take it up with him):

5.10
a. The heat of fusion for the ice-water phase transition is 335 kJ/kg at 0 degrees C and 1 bar. The density of water is 1000 kg/m^3 at these conditions, and that of ice is 915 kg/m^3. Develop an expression for the change of the melting temperature of ice with pressure.

b. The heat of vaporization for the steam-water phase transition is 2255 kJ/kg at 100 degrees C and 1 bar. Develop an expression for the change in boiling temperature of water with pressure.

c. Compute the freezing and boiling points of water in Denver, Colorado, where the mean atmospheric pressure is 84.6 kPa.

a) along the coexistence curve:

(?P/?T) = H/TV => dP/dlnT = H/V

=> dP/dlnT = H/V = [H(liquid) - H(solid)]/[V(liquid) - V(solid)] = [335,000 J/kg]/[1000^-1 - 915^-1 m^3/kg]

= -3.61x10^9 J/m^3 = -3.61x10^9 Pa

=> P2 = P1 - 3.61x10^9 ln(T2/T1) Pa

or

T2 = T1exp(-(P2-P1)/(3.61x10^9 Pa)

b)

dP/dT = H/TV ~ H/TV(vapor) V(vapor) >> V(liquid)
~ PH/RT^2 => V(vapor) = RT/P

dlnP/dT = H/RT^2 , now, assuming H is essentially constant

ln P2/P1 = - [H/R]*[1/T2 - 1/T1]

or T2 = [1/T1 - (R/H)*ln(P2/P1)]^-1 = [1/T1 - (8.314 J/molK)/(2,255,000 J/kg)*(1000 mol/kg-mol)/(18 kg/kg-mol)*ln(P2/P1)]^-1

c) if the pressure in Denver is 84.6 kPa:

T2(freezing) = 273.15exp[-(84,600-100,000)/(3.61x10^9)]
=~ 273.15 = T1(freezing) essentially no change

T2(boiling) = [(1/373.15) - ((8.314)(1000))/((2.255x10^6)(18))*ln(84.6/100)]^-1

=~ 368.44 K = 95.29 degrees C



[Edited on December 29, 2005 at 5:19 AM. Reason : Note: the question marks should be deltas]

12/29/2005 5:11:14 AM

drunknloaded
Suspended
147487 Posts
user info
edit post

honestly without getting any formal education that asked this exact question

everyone know water boils in colorado at like 205 degrees or some shit and everyone knows that boiling temp they always say in text books is like 212 so if it boils at a colder temperature i would guess it freezes 7 or so degrees after 32 so my guess is 39

someone pm me with the right answer so i know if i should stay at state or not

12/29/2005 5:46:47 AM

EhSteve
All American
7240 Posts
user info
edit post

The freezing point doesn't change much with pressure.

That's why you get that nearly vertical line between liquid and solid on the P vs. T diagram.

12/29/2005 5:58:43 AM

jakis
Suspended
1415 Posts
user info
edit post

Quote :
"Real Name : Jason
Age : 22
Sex : M
Class : Senior
Major : COM"

12/29/2005 1:46:56 PM

24carat
Veteran
309 Posts
user info
edit post

EhSteve is correct.

But, even without any math, you can see it quite easily in the first graph darkone posted. I put in some hints for you below (with apologies to the many of you who don't need any help with it.)

Look at the chart and find the solid, liquid, and vapor phases.
The small "E" on the graph marks normal conditions at room temperature at sea level.
The melting/freezing point line is the black line between the solid and liquid phases just to the left of the little "E." Do you see the large section that is almost exactly vertical? That shows that with large changes in pressure (which is the same as large changes in altitude), the temperature of the phase change is the same. In other words, the Temperature value on that black line is the same (~273.15 K) regardless of whether the pressure is 1 kiloPascals or 10 megaPascals. Can you find the points on the line and convince yourself of that?

Now look at the line between liquid and vapor. It is not vertical and indicates that, as pressure drops even slightly (which it does as you increase altitude), the temperature also drops. The lower atmospheric pressure is why water boils at lower temp in Denver, and also the reason for high altitude directions for things like cake mixes.

12/29/2005 2:39:03 PM

humandrive
All American
18286 Posts
user info
edit post

Again

Quote :
"For all practical purposes, there is no change in the freezing point of water with a change in elevation. "


There, this is over and done with.

12/29/2005 6:30:01 PM

HockeyRoman
All American
11811 Posts
user info
edit post

And be glad that is the case or else it may not ever rain.

12/30/2005 6:22:02 AM

 Message Boards » The Lounge » question about freezing temp/32 deg. at sea level Page [1]  
go to top | |
Admin Options : move topic | lock topic

© 2024 by The Wolf Web - All Rights Reserved.
The material located at this site is not endorsed, sponsored or provided by or on behalf of North Carolina State University.
Powered by CrazyWeb v2.39 - our disclaimer.