Is the Kinetic Energy of Water at 0°C Greater Than Ice at 0°C?

AI Thread Summary
The average kinetic energy of water at 0°C is equal to that of ice at the same temperature, despite the confusion surrounding potential and kinetic energy. When ice melts, energy is added to break the bonds, increasing potential energy rather than kinetic energy. The temperature measured by a thermometer reflects the average kinetic energy of the molecules, which remains consistent for both states at 0°C. The latent heat of fusion involves energy that breaks bonds, thus increasing potential energy while not affecting the kinetic energy at that temperature. Understanding these energy dynamics clarifies that both water and ice at 0°C have the same average kinetic energy.
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Homework Statement


The average kinetic energy of water at 0 °C is __________ the average kinetic energy of ice at 0 °C.

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The Attempt at a Solution


I said that it is greater than because when ice melts, energy is added to break the potential energy (bonds). I also know that average kinetic energy is directly linked to temperature so if they are at the same temperature, the average kinetic energy should be the same. The thing that is confusing me is that when the latent heat of fusion is applied to the ice, it breaks the bonds so it releases the potential energy so shouldn't the kinetic energy of water be higher than ice?

Cheers!
 
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TT0 said:
I said that it is greater than because when ice melts, energy is added to break the potential energy (bonds).
Isn't that adding potential energy?

When a thermometer measures temperature, what is it actually responding to?
 
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It is responding to the kinetic energy, but when the latent heat of fusion is applied, doesn't it break the bonds so therefore the potential energy would decrease? I am pretty sure this is wrong but I don't understand why. For example I think water has a lot of potential energy in its bonds and this potential energy is lost when it turns into gas because the bonds are broken. The potential energy is transferred into something which I am not sure of. Please help, thanks!
 
TT0 said:
It is responding to the kinetic energy, but when the latent heat of fusion is applied, doesn't it break the bonds so therefore the potential energy would decrease? I am pretty sure this is wrong but I don't understand why. For example I think water has a lot of potential energy in its bonds and this potential energy is lost when it turns into gas because the bonds are broken. The potential energy is transferred into something which I am not sure of. Please help, thanks!
You have the changes in PE backwards. To break a bond you have to inject energy, just as you have to supply energy to send a rocket up, overcoming the attraction of the earth. The PE increases.
 
I see thanks!
 

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