Thermodynamics question(change of internal energy)

In summary, the internal energy of a thermodynamic system is the total energy contained within the system and is represented by the symbol U. The change in internal energy affects the temperature of a system, with an increase in internal energy leading to an increase in temperature. The change in internal energy can be negative, resulting in a decrease in temperature. It is related to the change in enthalpy, which takes into account the work done by the system. The change in internal energy is not the same as the change in heat, as the former is a state function and the latter is a path function. However, the change in internal energy is equal to the heat added to the system plus the work done by the system.
  • #1
Devald
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The temperature of 2 kg of N2 changes from 300 K to 1000 K. Calculate the change of its internal
energy during this process, assuming the ideal gas behavior, in two different methods:
(1) Using constant heat capacity
(2) Using the enthalpy function


ı have to solve this question but ı can not sure about which equation should ı use..constant volume process or constant pressure process??ın other words how can ı sure about volume and pressure are constant ? Thanks
 
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  • #2
How is the internal energy of an ideal gas related to its temperature?

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Related to Thermodynamics question(change of internal energy)

1. What is the definition of "internal energy" in thermodynamics?

The internal energy of a thermodynamic system is the total energy contained within the system, including the kinetic and potential energy of all particles making up the system. It is a state function and is usually represented by the symbol U.

2. How does the change in internal energy affect the temperature of a system?

According to the First Law of Thermodynamics, the change in internal energy of a system is equal to the heat added to the system minus the work done by the system. Therefore, an increase in internal energy leads to an increase in temperature, and vice versa.

3. Can the change in internal energy be negative?

Yes, the change in internal energy can be negative. This means that the system has lost energy, either through heat transfer to the surroundings or work done by the system. This usually results in a decrease in temperature.

4. How is the change in internal energy related to the change in enthalpy?

The change in enthalpy (ΔH) is equal to the change in internal energy (ΔU) plus the product of pressure and change in volume (PΔV). This relationship is expressed in the equation ΔH = ΔU + PΔV. Enthalpy takes into account the work done by the system, whereas internal energy does not.

5. Is the change in internal energy the same as the change in heat?

No, the change in internal energy (ΔU) and the change in heat (Q) are not the same. While ΔU is a state function and depends only on the initial and final states of the system, Q is a path function and depends on the specific path taken by the system during the process. However, the change in internal energy is equal to the heat added to the system plus the work done by the system (ΔU = Q + W).

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