Entropy as function

Enthalpy and Entropy as Functions of T and P At constant composition the molar thermodynamic properties are functions of temperature and pressure (Postulate 5). Thus... 

Fig. 8. Sketch of the communal entropy as function of the fraction of liquidlike cells p.

Figure A3.4.1. Concentration and entropy as functions of time for reaction equation (A3.4.8). is the maximum value of the entropy ([20]). 

Thermodynamics. (21) This is to determine the vdume and entropy as functions of T and P by using equation 8. It involves the eos and the temperature dependent conOgimitional heat capacity Cn at atmospheric pressure. The polymer of choice was Bisphend-A-Polycaibonate. The eos and positron data are available. (22,23) The total heat capacity Cp of the glass is linear in T. (24) The assumption then is a corresponding expression for Cp (config.). 

For a semicrystalline polymer of your choice (other than those in Figs. 2-19-2-29), develop charts for enthalpy and entropy as functions of temperature and pressure. Use a datum of 25°C and atmospheric pressure. 

The whole of classical thermodynamics is based on the empirical laws which lead to the notions of temperature, internal energy and entropy as functions of state. At no point in the development of these laws, or of their consequences, does any reference need to be made to the idea that matter consists of ultimate particles, i.e. the atomic theory. But thermodynamics gives an insight neither into the possible origin of its laws nor any means of making a direct calculation of the thermodynamic properties of a substance. It is the purpose of statistical mechanics to advance knowledge in both of these directions. 

Figure 11.6 Enthalpy and entropy as functions of advancement at constant T and p. The curves are for a reaction A 2B with positive Ar// taking place in an ideal gas mixture with initial amounts nA,o = 1 mol and b,o = 0.

The two laws of thermodynamics establish energy and entropy as functions of state, making them functions of many variables. As we have seen. 

For monatomic, diatomic, and polyatomic gases, the TDF code may be used to calculate the free energy, enthalpy, and entropy as functions of temperature. The moments of inertia can be calculated for the polyatomic case. For one-Debye Theta and two-Debye Theta solids, the heat capacity is computed as a function of temperature in addition to the free energy, enthalpy, and entropy. These functions are fit to a fourth degree polynomial by the method of least squares. The integration constant, IC, in the equation H° — H° = J T dS/dT) + IC is computed from the fit of entropy as a function of temperature. 

---