Is Internal Energy Always Proportional to Temperature?

In summary, Internal energy and temperature are directly related, as an increase in internal energy results in an increase in temperature. However, in an isothermal situation, where the temperature remains constant, the change in internal energy is 0. This is because during a conversion of state, such as from a solid to a liquid, energy is used to change the state of the matter rather than increase its temperature. Therefore, when determining the energy required to convert matter from one state to another, the energy needed to raise the temperature must be added to the energy needed for the phase change. This is why ice and water can coexist at the same temperature of 0 degrees Celsius.
  • #1
jack1234
133
0
Internal energy vs temperature(q37)

For this question:
http://tinyurl.com/3ymlnj

The answer to this question is c.

But according to my understanding, increasing of internal energy means increasing of temperature. Hence is isothermal situation, the change of internal energy is 0.
With this understanding, if c is the answer, b will be the answer.

But now b is not the answer, hence I wish to know is there anything wrong with this understanding?
 
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  • #2
conversion of state (for example: from a solid to a liquid) costs energy, and while the energy is going into converting the state of the matter, it doesn't go into raising the temperature of it.

So when we find out how much energy it takes to make -5 degree ice into 7 degrees water, we have to add together:

1) the energy it takes to raise it from -5 to 0 degrees C
2) the energy it takes to convert it from ice to water
3) the energy it takes to raise it from 0 to 7 degrees C

so when matter is at its melting or boiling points (it's temperature of phase change) it can exist in both phases with that same temperature. Ice and water can both exist at 0 degrees C (32 F)
 
  • #3


Thank you for your question. I can understand why there may be some confusion here. While it is true that increasing internal energy can lead to an increase in temperature, it is not always the case. Internal energy is a measure of the total energy contained within a system, including both kinetic and potential energy. Temperature, on the other hand, is a measure of the average kinetic energy of the particles within a system. So while increasing internal energy may often result in an increase in temperature, it is not a direct relationship. Other factors, such as the type of particles and their interactions, can also affect temperature.
In an isothermal situation, there is no change in temperature, but there can still be changes in internal energy. This is because the system can exchange energy with its surroundings, such as through work or heat transfer, without changing its temperature. Therefore, while it is true that an increase in internal energy can often lead to an increase in temperature, it is not always the case and there are other factors to consider. I hope this clarifies any confusion you may have had.
 

FAQ: Is Internal Energy Always Proportional to Temperature?

What is the relationship between internal energy and temperature?

The internal energy of a system is directly proportional to its temperature. As the temperature increases, the internal energy also increases. This is because at higher temperatures, the molecules in the system have more kinetic energy and are moving faster, resulting in a higher internal energy.

How does internal energy change with temperature?

As mentioned before, the internal energy of a system increases with temperature. This is because as the temperature increases, the molecules in the system have more kinetic energy, leading to an increase in the overall internal energy of the system.

Can internal energy and temperature be measured separately?

Yes, internal energy and temperature can be measured separately. Internal energy is a measure of the total energy of a system, while temperature is a measure of the average kinetic energy of the molecules in the system. Both can be measured using different instruments and techniques.

Is there a limit to how much internal energy a system can have at a certain temperature?

Yes, there is a limit to how much internal energy a system can have at a certain temperature. This is known as the maximum internal energy, and it is reached when all the molecules in the system are moving at their maximum possible speed. This limit is different for each substance and is known as the specific heat capacity.

How does the internal energy of a system affect its physical properties at different temperatures?

The internal energy of a system plays a significant role in determining its physical properties at different temperatures. As the internal energy increases, the system may undergo phase changes (e.g. from solid to liquid to gas) or exhibit different behaviors, such as expansion or contraction. Changes in internal energy can also affect the electrical, magnetic, or thermal properties of a system.

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