What have you done to try to work this out?Hong1111 said:For an ideal gas, how to prove that:
(a) its internal energy does not change with volume at constant temperature
(b) its enthalpy does not change with pressure at constant temperature
Thanks.
RedX said:Well for an ideal gas, they are like free particles as there are no forces or potential energies between particles. If you increase the size of the box, that doesn't change the potential energy since there is no potential energy. It doesn't change the kinetic energy because all collisions with the box are elastic, so colliding with the walls doesn't change the kinetic energy, so changing the frequency of collision with walls (which would alter the pressure) by changing how big the box is does not change the kinetic energy! So since internal energy is kinetic+potential, none of this changes with the size of the box!
As for enthalpy I have no clue what that is.
Thermodynamics is the branch of physics that deals with the study of heat and its relationship to energy and work. It also involves the study of the behavior of matter and its changes in temperature, pressure, and volume.
An ideal gas is a theoretical gas that follows certain assumptions, such as having particles with no volume and no intermolecular forces. It is used as a simplified model for real gases in order to make calculations easier.
In order to keep temperature constant, the gas is placed in a container that is surrounded by a thermostat, which maintains a constant temperature. The container is also insulated to prevent any heat exchange with the surrounding environment.
According to the ideal gas law, the relationship between temperature and pressure in an ideal gas is directly proportional. This means that as temperature increases, so does pressure, and vice versa, as long as the volume and number of particles remain constant.
In order to prove the thermodynamics of an ideal gas at constant temperature, experiments are conducted to measure the changes in pressure and volume of the gas while keeping the temperature constant. These results are then compared to the theoretical predictions based on the ideal gas law, and if they match, it can be concluded that the thermodynamics of the ideal gas at constant temperature is valid.