'Splain this

for water to freeze it has to give off heat. the heat from the first bottle kept the other from freezing
 
To try and make my earlier comment clearer, between two otherwise isolated open systems an adiabatic wall is by definition impossible. This problem is solved by recourse to the principle of conservation of energy. This principle allows a composite isolated system to be derived from two other component non-interacting isolated systems, in such a way that the total energy of the composite isolated system is equal to the sum of the total energies of the two component isolated systems. Two previously isolated systems can be subjected to the thermodynamic operation of placement between them of a wall permeable to matter and energy, followed by a time for establishment of a new thermodynamic state of internal equilibrium in the new single unpartitioned system. The internal energies of the initial two systems and of the final new system, considered respectively as closed systems as above, can be measured. Then the law of conservation of energy requires that: Δ U s + Δ U o = 0 , {\displaystyle \Delta U_{s}+\Delta U_{o}=0\,,} where ΔUs and ΔUo denote the changes in internal energy of the system and of its surroundings respectively. This is a statement of the first law of thermodynamics for a transfer between two otherwise isolated open systems. For the thermodynamic operation of adding two systems with internal energies U1 and U2, to produce a new system with internal energy U, one may write U = U1 + U2; the reference states for U, U1 and U2 should be specified accordingly, maintaining also that the internal energy of a system be proportional to its mass, so that the internal energies are extensive variables. There is a sense in which this kind of additivity expresses a fundamental postulate that goes beyond the simplest ideas of classical closed system thermodynamics; the extensivity of some variables is not obvious, and needs explicit expression Also of course: Δ N s + Δ N o = 0 , {\displaystyle \Delta N_{s}+\Delta N_{o}=0\,,} where ΔNs and ΔNo denote the changes in mole number of a component substance of the system and of its surroundings respectively.
 
BigClay said:
To try and make my earlier comment clearer, between two otherwise isolated open systems an adiabatic wall is by definition impossible. This problem is solved by recourse to the principle of conservation of energy. This principle allows a composite isolated system to be derived from two other component non-interacting isolated systems, in such a way that the total energy of the composite isolated system is equal to the sum of the total energies of the two component isolated systems. Two previously isolated systems can be subjected to the thermodynamic operation of placement between them of a wall permeable to matter and energy, followed by a time for establishment of a new thermodynamic state of internal equilibrium in the new single unpartitioned system. The internal energies of the initial two systems and of the final new system, considered respectively as closed systems as above, can be measured. Then the law of conservation of energy requires that: Δ U s + Δ U o = 0 , {\displaystyle \Delta U_{s}+\Delta U_{o}=0\,,} where ΔUs and ΔUo denote the changes in internal energy of the system and of its surroundings respectively. This is a statement of the first law of thermodynamics for a transfer between two otherwise isolated open systems. For the thermodynamic operation of adding two systems with internal energies U1 and U2, to produce a new system with internal energy U, one may write U = U1 + U2; the reference states for U, U1 and U2 should be specified accordingly, maintaining also that the internal energy of a system be proportional to its mass, so that the internal energies are extensive variables. There is a sense in which this kind of additivity expresses a fundamental postulate that goes beyond the simplest ideas of classical closed system thermodynamics; the extensivity of some variables is not obvious, and needs explicit expression Also of course: Δ N s + Δ N o = 0 , {\displaystyle \Delta N_{s}+\Delta N_{o}=0\,,} where ΔNs and ΔNo denote the changes in mole number of a component substance of the system and of its surroundings respectively.
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It should be noted that I got a "D" in thermo - actually a good grade considering 70%+ failed, but that doesn't mean I learned anything... well, empirical data involving beer, but otherwise, nothing. ;-)
 
Fabrik8 said:
If the ice isn't completely frozen, it will hold the cooler temperature at the freezing point until completely frozen, then the temp will decrease eventually down to the 12deg outside temp. The water actually releases heat during the phase change from liquid to solid, which is why the temp stays at 32 deg until totally frozen. Beer doesn't freeze at 32deg, because of the alcohol. So yeah, ice makes a good thermal buffer for the beer, especially when the beer is already above freezing and has some heat to release in the cooler.

You're way smarter than all those people who think you're insane for using ice in a cooler with beer. If I saw you do that, I would laugh because you're obviously a badass, and then I'd buy you some beer for the cooler. Because, you know, scientific research.
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I favor research... ;-)
 
BigClay said:
To try and make my earlier comment clearer, between two otherwise isolated open systems an adiabatic wall is by definition impossible. This problem is solved by recourse to the principle of conservation of energy. This principle allows a composite isolated system to be derived from two other component non-interacting isolated systems, in such a way that the total energy of the composite isolated system is equal to the sum of the total energies of the two component isolated systems. Two previously isolated systems can be subjected to the thermodynamic operation of placement between them of a wall permeable to matter and energy, followed by a time for establishment of a new thermodynamic state of internal equilibrium in the new single unpartitioned system. The internal energies of the initial two systems and of the final new system, considered respectively as closed systems as above, can be measured. Then the law of conservation of energy requires that: Δ U s + Δ U o = 0 , {\displaystyle \Delta U_{s}+\Delta U_{o}=0\,,} where ΔUs and ΔUo denote the changes in internal energy of the system and of its surroundings respectively. This is a statement of the first law of thermodynamics for a transfer between two otherwise isolated open systems. For the thermodynamic operation of adding two systems with internal energies U1 and U2, to produce a new system with internal energy U, one may write U = U1 + U2; the reference states for U, U1 and U2 should be specified accordingly, maintaining also that the internal energy of a system be proportional to its mass, so that the internal energies are extensive variables. There is a sense in which this kind of additivity expresses a fundamental postulate that goes beyond the simplest ideas of classical closed system thermodynamics; the extensivity of some variables is not obvious, and needs explicit expression Also of course: Δ N s + Δ N o = 0 , {\displaystyle \Delta N_{s}+\Delta N_{o}=0\,,} where ΔNs and ΔNo denote the changes in mole number of a component substance of the system and of its surroundings respectively.
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What you talkin' bout Willis Compilation - YouTube
 
And here, I thought I was the only Physicist on board...Party on, fellow si-intistic wheelers!

hey-this-is-si-intistic-stuff-jack.jpg
 
BigClay said:
To try and make my earlier comment clearer, between two otherwise isolated open systems an adiabatic wall is by definition impossible. This problem is solved by recourse to the principle of conservation of energy. This principle allows a composite isolated system to be derived from two other component non-interacting isolated systems, in such a way that the total energy of the composite isolated system is equal to the sum of the total energies of the two component isolated systems. Two previously isolated systems can be subjected to the thermodynamic operation of placement between them of a wall permeable to matter and energy, followed by a time for establishment of a new thermodynamic state of internal equilibrium in the new single unpartitioned system. The internal energies of the initial two systems and of the final new system, considered respectively as closed systems as above, can be measured. Then the law of conservation of energy requires that: Δ U s + Δ U o = 0 , {\displaystyle \Delta U_{s}+\Delta U_{o}=0\,,} where ΔUs and ΔUo denote the changes in internal energy of the system and of its surroundings respectively. This is a statement of the first law of thermodynamics for a transfer between two otherwise isolated open systems. For the thermodynamic operation of adding two systems with internal energies U1 and U2, to produce a new system with internal energy U, one may write U = U1 + U2; the reference states for U, U1 and U2 should be specified accordingly, maintaining also that the internal energy of a system be proportional to its mass, so that the internal energies are extensive variables. There is a sense in which this kind of additivity expresses a fundamental postulate that goes beyond the simplest ideas of classical closed system thermodynamics; the extensivity of some variables is not obvious, and needs explicit expression Also of course: Δ N s + Δ N o = 0 , {\displaystyle \Delta N_{s}+\Delta N_{o}=0\,,} where ΔNs and ΔNo denote the changes in mole number of a component substance of the system and of its surroundings respectively.
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All I'm hearing is:

 
I remember a school science project eons ago. Two dixie cups, one filled with cold tap water, and one with hot, placed in a freezer, and checked every ten minutes until they froze. At basically the same time, because the hot one had more heat to release, and did so faster, catching up to the cold one. That's all I got. Carry on.
 
BigClay said:
To try and make my earlier comment clearer, between two otherwise isolated open systems an adiabatic wall is by definition impossible. This problem is solved by recourse to the principle of conservation of energy. This principle allows a composite isolated system to be derived from two other component non-interacting isolated systems, in such a way that the total energy of the composite isolated system is equal to the sum of the total energies of the two component isolated systems. Two previously isolated systems can be subjected to the thermodynamic operation of placement between them of a wall permeable to matter and energy, followed by a time for establishment of a new thermodynamic state of internal equilibrium in the new single unpartitioned system. The internal energies of the initial two systems and of the final new system, considered respectively as closed systems as above, can be measured. Then the law of conservation of energy requires that: Δ U s + Δ U o = 0 , {\displaystyle \Delta U_{s}+\Delta U_{o}=0\,,} where ΔUs and ΔUo denote the changes in internal energy of the system and of its surroundings respectively. This is a statement of the first law of thermodynamics for a transfer between two otherwise isolated open systems. For the thermodynamic operation of adding two systems with internal energies U1 and U2, to produce a new system with internal energy U, one may write U = U1 + U2; the reference states for U, U1 and U2 should be specified accordingly, maintaining also that the internal energy of a system be proportional to its mass, so that the internal energies are extensive variables. There is a sense in which this kind of additivity expresses a fundamental postulate that goes beyond the simplest ideas of classical closed system thermodynamics; the extensivity of some variables is not obvious, and needs explicit expression Also of course: Δ N s + Δ N o = 0 , {\displaystyle \Delta N_{s}+\Delta N_{o}=0\,,} where ΔNs and ΔNo denote the changes in mole number of a component substance of the system and of its surroundings respectively.
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You must have cut and pasted that from somewhere; the "\displaystyle" gives it away. :D
 
I think it's pretty simple...

Does the frozen one contain sodium bicarbonate? I can see that the unfrozen one does.

I saw this first hand this past Sunday as I was assembling a big ass play set for a friend's kid. It was blowing 20mph and it was 29 degrees here. My bottle of Sam's Choice water froze while we were working and my buddy's bottle didn't...it was Food Lion water.
 
Co-worker and I were discussing this today and he brought up a good point. Newton's law of cooling states that the rate of heat loss of a body is directly proportional to the difference in the temperatures between the body and its surroundings provided the temperature difference is small and the nature of radiating surface remains same. As such, it is equivalent to a statement that the heat transfer coefficient, which mediates between heat losses and temperature differences, is a constant. This condition is generally true in thermal conduction (where it is guaranteed by Fourier's law), but it is often only approximately true in conditions of convective heat transfer, where a number of physical processes make effective heat transfer coefficients somewhat dependent on temperature differences.
 
That, or....

Sodium bicarbonate and calcium chloride?
 
There are obviously some fairly complex thermodynamic processes at play here, but all things considered...

Croatan_Kid said:
That, or....

Sodium bicarbonate and calcium chloride?
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Sometimes the simplest answer is likely the (or at least "a") correct one. NaHCO3 (Sodium bicarbonate), otherwise known as baking soda, is a form of salt. It induces an exothermic process when mixed with water, also resulting in a lower freezing point. Same reason why road salt keeps snow from freezing on the road (or melts snow/ice). Calcium chloride follows very similar reactions.

yes-winning.jpg
 
BigClay said:
This is an easy one, it is based on the pressure within the atmosphere of Earth (or that of another planet). In most circumstances atmospheric pressure is
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Sorry that's as far as I got.I knew by then it would be above my pay grade.
 
So I did this a little while ago (this morning) with a partial bottle that had been sitting in my cupholder all week. It was unfrozen liquid, so I opened it (the bottle was slightly collapsed because of the low pressure in the bottle), and then shook it. It turned to icy slush in about 2 seconds, with the ice formation starting from a certain point and travelling across the water.
 
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