Review of Chemical Principles

This chapter reviews those chemical principles that will be particularly useful for a fundamental understanding of soil chemistry. The reader may not wish to read this chapter before going on to the main text dealing with soil chemistry, but may prefer to refer back to specific sections within this chapter when unfamiliar or difficult chemical concepts are encountered in the text. 

THE NECESSARY CONCEPTS 1.2a. Gram Molecular Weight (Mole) 

In soil chemistry, mole is also used to denote Avogadro s number of fundamental charge units on surfaces or ions, symbolized by mole(+) or mole(—) depending on the sign of the charge. For example, 1 mole of Ca ions carries 2 moles(+) of charge. 

The important kinds of bonds formed between atoms are summarized below. 

Ionic Bonding. This form of bonding esults if the outer valence electrons of two atoms, A and B, are of very different energies, so that transfer of one or more electrons occurs  

---

The chapter starts with a brief review of thermodynamic principles as they apply to the concept of the chemical equilibrium. That section is followed by a short review of the use of statistical thermodynamics for the numerical calculation of thermodynamic equilibrium constants in terms of the chemical potential (often designated as (i). Lastly, this statistical mechanical development is applied to the calculation of isotope effects on equilibrium constants, and then extended to treat kinetic isotope effects using the transition state model. These applications will concentrate on equilibrium constants in the ideal gas phase with the molecules considered in the rigid rotor, harmonic oscillator approximation. 

A theoretical account from the point of view of DFT could be found in [1, 42,43]. For a good review of chemical applications of the above principles as described by quantum chemical methods in general and density functional methods in particular see the papers of Geerlings and De Proft [4,44,45]. 

Much of the increasing interest in exploiting the effects of high pressures is based on research carried out on the thermodynamic and chemical principles that support HP. In order to understand about actual and potential applications of HP on foods, a short review of those principles are presented in this contribution. 

A review of First Principles simulation of oxide surhices is presented, focussing on the interplay between atomic-scale structure and reactivity. Practical aspects of the First Principles method are outlined choice of functional, role of pseudopotential, size of basis, estimation of bulk and surface energies and inclusion of the chemical potential of an ambient. The suitability of various surface models is discussed in terms of planarity, polarity, lateral reconstruction and vertical thickness. These density functional calculations can aid in the interpretation of STM images, as the simulated images for the rutile (110) surface illustrate. Non-stoichiometric reconstructions of this titanium oxide surface are discussed, as well as those of ruthenium oxide, vanadium oxide, silver oxide and alumina (corundum). This demonstrates the link between structure and reactivity in vacuum versus an oxygen-rich atmosphere. This link is also evident for interaction with water, where a survey of relevant ab initio computational work on the reactivity of oxide surfaces is presented. 

X-ray ray photoelectron spectroscopy (XPS) characterizes the chemical state and elemental abundance of the near-surface by measuring the kinetic energy and intensity of photoelectrons excited by irradiation of a sample (Raeburn et al. 1997b). Excellent reviews of the principles and instrumentation for XPS can be found in Hochella (1988), Turner and Schreifels (2000), and Tonner et al. (1999). 

Miller BL (2010) Nano-structured silicon optical sensors. In Zourob MLA (ed) Optical guided-wave chemical and biosensors II, vol 8, p 3 Springer-Verlag Berlin, Heidelberg Nirschl M, Reuter F, Voros J (2011) Review of transducers principles for label-free biomolecular interaction analysis. Biosensors 1 70... 

C) Review of the principles and practices for analyzing an incident to determine the hazardous substances present, their physical and chemical properties, the likely behavior of the hazardous substance and its container, the types of hazardous substance transportation containers and vehicles involved in the release, the appropriate strategy for approaching release sites and containing the release. 

M odern studies of the atmosphere, oceans, and earth and planetary systems demand a sound knowledge of basic chemical principles. This book provides a clear, concise review of these principles, particularly relating to riie atmosphere. Students with little formal training in chemistry can work through the chapters and numerous exercises wirfiin rt>is book before accessing the standard texts in the atmospheric and environmental sciences. 

This volume, a companion to Heavy Metals in Natural Waters, provides a unique review of the principles and methods of monitoring and assessing the pollution of natural waters by organic chemicals. 

The reader unfamiliar with basic chemistry and the way that chemists draw molecules should not be waylaid by all of the chemical drawings that are given in early chapters. Certainly, the ideas and principles may be understood without appreciation for the three-dimensional structures. The reader is especially encouraged to continue forward to Chapters 6-8, where photographs and diagrams of familiar objects are used to illustrate how chirality is present in the macroscopic world. Many readers who are far removed from their chemistry studies may benefit from the quick review of chemical structural drawings given in the short appendix at the end of the book. 

In this paper, the classical TSC spectrum of amorphous polymers will be presented after a brief review of the principles of TSC. Then, the influence of molecular weight, chemical structure, and physical parameters, such as orientation and thermodynamic history, will be presented. 

Professionals (especially environmental practitioners) who need a quick review of chemical safety and health principles and applications... 

A brief description of a low-density non-equilibrium plasma is given followed by a review of its characteristic features and of tire relevant collisionprocesses in tire plasma. Principles for tire generation of plasmas in teclmical devices are discussed and examples of important plasma chemical processes and tlieir technical applications are presented. 

---