Chemical composition gravitational fields, effects

The observations on which thermodynamics is based refer to macroscopic properties only, and only those features of a system that appear to be temporally independent are therefore recorded. This limitation restricts a thermodynamic analysis to the static states of macrosystems. To facilitate the construction of a theoretical framework for thermodynamics [113] it is sufficient to consider only systems that are macroscopically homogeneous, isotropic, uncharged, and large enough so that surface effects can be neglected, and that are not acted on by electric, magnetic or gravitational fields. The only mechanical parameter to be retained is the volume V. For a mixed system the chemical composition is specified in terms of the mole numbers Ni, or the mole fractions [Ak — 1,2,..., r] of the chemically pure components of the system. The quantity V/(Y j=iNj) is called the molar... 

Phase equilibrium is the science that allows us to determine the physical properties of the phases that exist at this equilibrium condition. In general, phase equilibria deals with all combinations of vapor, liquid, and solid phases. This chapter will present the basic concepts and models to allow for the determination of the equilibrium compositions of these phases in combinations with each other. In this chapter, we will be not consider chemical and nuclear reactions, surface and tensile effects, or the effect of a gravitational or electromagnetic fields. 

Isotope effects can be divided in two main groups phenomena that are directly connected to the differences in the molecular mass (thermal motion, motion in gravitational, electric, and other fields) and those connected to different mass distributions within the molecule (isotope effects on molecular spectra, chemical equilibria, reaction rate, etc.). Isotope effects may also be classified according to the field in which they are observed physics, chemistry, biology, geology, spectroscopy, etc. Isotope effects play an important role in the variation of stable isotope compositions in nature. The differences in chemical and physical properties of the isotopes form the basis of their separation from each other and make possible the production of enriched isotopes for industrial, military, medical, and research purposes (see Chap. 51 in Vol. 5). 

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