how is internal energy of a real gas differs from that of ideal gas?
Please write the difference in details
The internal energy of a gas is the sum of the kinetic and potential energies of its individual molecules. In the case of an ideal gas, it is assumed that the gas molecules do not interact with each other except during collisions. Therefore, the internal energy of an ideal gas depends solely on the temperature and is independent of the volume or pressure of the gas.
On the other hand, a real gas differs from an ideal gas because its molecules do interact with each other. These intermolecular forces can influence the behavior of the gas and result in deviations from ideal gas behavior. This interaction between gas molecules leads to differences in the internal energy of a real gas compared to an ideal gas. Here are some key differences in more detail:
1. Dependence on volume: In an ideal gas, the internal energy is independent of the volume of the gas because there are no intermolecular forces to consider. However, in a real gas, the internal energy may also depend on the volume due to interactions between gas molecules. For example, when a real gas is compressed or expanded, the intermolecular forces can change, thereby affecting the internal energy.
2. Dependence on pressure: Similarly, for an ideal gas, the internal energy is also independent of pressure. But for a real gas, the intermolecular forces can cause changes in internal energy when the pressure is altered. This happens because changes in pressure can influence molecular interactions, affecting the internal energy.
3. Phase transitions: Real gases can undergo phase transitions such as condensation or liquefaction, which involve a significant change in the internal energy. These phase transitions are a consequence of the intermolecular forces acting between the gas molecules. Ideal gases do not experience such phase transitions.
4. Departure from ideal gas law: Real gases often deviate from the ideal gas law, PV = nRT, due to intermolecular interactions. This deviation can manifest as greater or lesser compressibility compared to an ideal gas, resulting in differences in internal energy.
In summary, the internal energy of a real gas differs from that of an ideal gas due to the interactions between gas molecules. These interactions cause dependencies on volume, pressure, and can lead to phase transitions. These differences make the behavior of real gases more complex to analyze compared to ideal gases.