- #1
atat1tata
- 29
- 0
In almost every textbook I have seen, pressure is said to be one of the most important state variables of a thermodynamical system. But if the system is three-dimensional and on planet Earth, it is not constant! This problem, however, is neglected in every reference I consulted.
It seems to me that it is to be addressed, since there is also potential energy (that makes the energy of the particles dependent on height) to consider.
The only solution I see is to assign a thermodynamical system for each infinitesimal height of the volume of the actual system. But considering, for example, a chemical reaction occurring in a bucket of water, how can it be described in terms of Gibbs free energy, that is useful only when the pressure is constant?
It seems to me that it is to be addressed, since there is also potential energy (that makes the energy of the particles dependent on height) to consider.
The only solution I see is to assign a thermodynamical system for each infinitesimal height of the volume of the actual system. But considering, for example, a chemical reaction occurring in a bucket of water, how can it be described in terms of Gibbs free energy, that is useful only when the pressure is constant?