- #1
steve oliver
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A book said that the PE of molecules increase during melting of ice but shouldn't it be decrease since the distance between molecules increase ?Isnt the force between the molecules determine the PE?
Change of state and potential energy
- Thread starter steve oliver
- Start date
In summary, the potential energy of molecules increases during the melting of ice due to the increase in distance between molecules. This is because the force between the molecules and potential energy are interlinked, and as the distance between molecules increases, so does the potential energy. This can be seen in the graph provided, where the "rest" state of the molecules is at a minimum potential energy. Additionally, the potential energy also increases if the distance between molecules decreases from this "rest" state. Further explanations and resources on melting ice and the properties of water can be found in related discussions and on Wikipedia.
- #2
H Smith 94
Gold Member
- 55
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You're right about the force ##F## and potential energy ##U## being interlinked. They have the following relation
[tex]U = -\frac{dF}{dr} \approx -\frac{\Delta F}{\Delta r}[/tex]
See the below figure.
[source]
The "rest" state of the molecules is at ##r_0##, where potential energy in minimum. If the distance increases from ##r_0##, it can be seen from the above graph that the potential energy will also increase.
[tex]U = -\frac{dF}{dr} \approx -\frac{\Delta F}{\Delta r}[/tex]
See the below figure.
[source]
The "rest" state of the molecules is at ##r_0##, where potential energy in minimum. If the distance increases from ##r_0##, it can be seen from the above graph that the potential energy will also increase.
- #3
BvU
Science Advisor
Homework Helper
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Well, if the distance decreases from ##r_0##, doesn't the potential energy increase also ?H Smith 94 said:
What does the graph represent in the context of melting ice ?
see other threads on melting water, e.g. this one
Wikipedia on ice and on properties of water is good, too.
Related to Change of state and potential energy
1. What is a change of state?
A change of state refers to the physical transformation of a substance from one state to another, such as from solid to liquid or liquid to gas.
2. What causes a change of state?
A change of state is caused by an increase or decrease in energy, typically in the form of heat. This added energy allows the atoms or molecules in a substance to overcome their intermolecular forces and change their arrangement into a different state.
3. What is potential energy?
Potential energy is the stored energy of an object or system. In the context of a change of state, potential energy refers to the energy stored in the bonds between particles in a substance.
4. How does potential energy change during a change of state?
Potential energy increases when a substance changes from a solid to a liquid, as the intermolecular forces weaken and the particles have more freedom to move. It also increases when a substance changes from a liquid to a gas, as the particles are further apart and have more kinetic energy.
5. Can potential energy be converted into other forms of energy during a change of state?
Yes, potential energy can be converted into kinetic energy during a change of state. When a substance changes from a solid to a liquid or a liquid to a gas, some of its potential energy is converted into kinetic energy as the particles gain more motion and energy.
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