- #1
ThomGunn
- 20
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I had a bottle half full of ice and filled it with water and placed it in my fridge. I noticed that the ice was taking a significant time to melt. In fact after half a day it looked like it hadn’t melted at all.
That got me to thinking. Say I did this with a rigid container and filled up the entire volume of the container with ice and water. Say 50-50. I’m curious if there is some combination of volume, concentration of water, and concentration of ice, that would allow for the ice to remain ice at say room temperature or any other temperature above freezing for a significant amount of time.
Normally this would be a simple calorimetry problem, and I’d use the conservation of energy and find an equilibrium temperature. However, allowing the system to interact with the environment is causing me some confusion. I obviously can’t have the mass of all the air in a room, but I would then treat the environment like a reservoir. So then the equilibrium temperature would have to be the temperature of the reservoir. Which would ensure that the ice would melt.
After thinking of that I got to thinking about how the volume of the container might play some role. I took my bottle out of the fridge and after a short while the ice melted and the sides of the bottle contracted as to indicate that there was some kind of vacuum present. This makes sense, Ice is less dense than water and thus must occupy a larger volume. I didn’t expect a vacuum to develop in such a way that the sides of the bottle would contract. So I got to thinking what would happen if the container was perfectly rigid. This is where I got into things I do not know about. I assume the ice would still melt and the container just wouldn’t crush. Since the volume in the container is fixed, would it be possible to set up the initial concentrations so that there is no space available for all of the ice to melt? Or would this always just lead to an increase in pressure, with the work being done by the reservoir? Allowing the ice to always melt? Lastly, could I calculate the rate at which the ice melts and how the initial conditions affect that rate? To determine if perhaps there is a way to slow the rate at which it melts, because I believe I can now conclude that the ice must melt….although I have no idea how to calculate at what speed this occurs.
Any help or direction would be appreciated. I believe my reasoning up to this point is sound, but if I’ve overlooked something I would very much appreciate you pointing it out
That got me to thinking. Say I did this with a rigid container and filled up the entire volume of the container with ice and water. Say 50-50. I’m curious if there is some combination of volume, concentration of water, and concentration of ice, that would allow for the ice to remain ice at say room temperature or any other temperature above freezing for a significant amount of time.
Normally this would be a simple calorimetry problem, and I’d use the conservation of energy and find an equilibrium temperature. However, allowing the system to interact with the environment is causing me some confusion. I obviously can’t have the mass of all the air in a room, but I would then treat the environment like a reservoir. So then the equilibrium temperature would have to be the temperature of the reservoir. Which would ensure that the ice would melt.
After thinking of that I got to thinking about how the volume of the container might play some role. I took my bottle out of the fridge and after a short while the ice melted and the sides of the bottle contracted as to indicate that there was some kind of vacuum present. This makes sense, Ice is less dense than water and thus must occupy a larger volume. I didn’t expect a vacuum to develop in such a way that the sides of the bottle would contract. So I got to thinking what would happen if the container was perfectly rigid. This is where I got into things I do not know about. I assume the ice would still melt and the container just wouldn’t crush. Since the volume in the container is fixed, would it be possible to set up the initial concentrations so that there is no space available for all of the ice to melt? Or would this always just lead to an increase in pressure, with the work being done by the reservoir? Allowing the ice to always melt? Lastly, could I calculate the rate at which the ice melts and how the initial conditions affect that rate? To determine if perhaps there is a way to slow the rate at which it melts, because I believe I can now conclude that the ice must melt….although I have no idea how to calculate at what speed this occurs.
Any help or direction would be appreciated. I believe my reasoning up to this point is sound, but if I’ve overlooked something I would very much appreciate you pointing it out
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