Geological problems often need to compare the entropy of different minerals. The formulas above show that external pressure must be used when calculating volumetric work. Formula t'! Infinite small amount of work takes up W, because W is not a state function and can not be expressed by total differential.
3. The mathematical expression of the first law is only that Zhang Baigong and heat are process variables. The numerical FTI of process variables depends not only on the initial state and final state, but also on the specific process. Joule heat work equivalent experiment proves that the work required to raise a certain amount of pure water to a certain temperature in adiabatic process is completely certain, regardless of the way of work. Generally speaking, when any system experiences different adiabatic processes from an initial state to a final state, the work in all these processes is the same. It is shown that the adiabatic work W must correspond to the change of a state function of the system.
This state function is the internal energy of the system in equilibrium, called thermodynamic energy, also known as internal energy. It refers to the sum of the energies attracting or repelling each other among the molecules in the system, the translational and rotational energies of the molecules, the vibrations of the atoms in the molecule, and the energies of the electrons and nuclear motions. Thermodynamic energy is the sum of all the energies of the various motions in the system. Thermodynamic energy is characterized by its extensibility. The Joule experimental results can be expressed as the thermodynamic energy of the initial and final states of the system in the W adiabatic-Uz-U1 one-state port (4-3) formula. The AU is the change of the thermodynamic energy. The above formula shows that the work obtained by the system in the adiabatic process is equal to the increment of the thermodynamic energy of the system. Formula 4-3 is the definition of thermodynamic energy and a special form of energy conservation principle applied under adiabatic conditions. If the heat is transferred without work, such as the heating of water, the results of reactive heating and adiabatic heating should be the same according to the thermal work equivalent.
If it is generalized to general cases, both work and heat are involved in the process, then the general formula is the first law of thermodynamics, and the written description is that the energy transmitted in the form of heat and work must be equal to the change of thermodynamic energy of the system.
Since the input and output of materials are not considered in the derivation process, formula (4-5) should be the first law of thermodynamics for closed systems and the principle of energy conservation for closed systems. Historically, some people have tried to build a kind of machine that can work without consuming energy. It is called the first kind of perpetual motion machine. Therefore, the first law of thermodynamics can also be expressed as the first kind of perpetual motion is impossible to achieve.
Now let's summarize the significance of the first law of thermodynamics. It assumes that there is a physical quantity called thermodynamic energy. This quantity depends on the state of the system, and has nothing to do with how to achieve this state. Each state has its thermodynamic energy. The first law of thermodynamics also embodies the application of the principle of conservation of energy to the variation of work and thermodynamic energy of the system. Finally, the first law of thermodynamics treats heat as a transfer energy in its formulation, so heat can be defined as the difference between the change of thermodynamic energy and the work done in an adiabatic process.
Here we will turn to geology and apply the first law to some practical problems. Assuming that we can measure the thermal effect of coltan transformed into calcite at 25 C and 1.013 I05 Pa, the volume of J. calcite is 36.934 cms. Tiano1, and the volume of coltan is 34.15 C. Tian 3.mol-. Based on these data, we can calculate the thermodynamic energy change of the reaction from aragonite to calcite.