An Introduction to Environmental Organic Chemicals

Elemental Composition, Molecular Formula, and Molar Mass Electron Shells of Elements Present in Organic Compounds Covalent Bonding 

Bond Energies (Enthalpies) and Bond Lengths. The Concept of Electronegativity 

Oxidation State of the Atoms in an Organic Molecule Illustrative Example 2.1 Determining the Oxidation States of the Carbon Atoms Present in Organic Molecules The Spatial Arrangement of the Atoms in Organic Molecules Delocalized Electrons, Resonance, and Aromaticity 

3 Classification, Nomenclature, and Examples of Environmental Organic Chemicals 

Some Additional Examples of Compounds Exhibiting More Complex Structures 

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Chemistry is involved at every stage of the process, including the chemistry of inorganic pigments and organic resins, colloid and surface chemistry, as well as elements of environmental and analytical chemistry. The Chemistry of Paper provides an informative and entertaining overview of the chemical principles involved. It will be especially suitable to students and others who require an introduction to the chemistry of paper manufacture. 

In summary, the movement of a chemical through the environment follows a set of pathways, each one resulting from a unique combination of pure chance with the laws of physics, chemistry, and biochemistry. Exposure occurs when a population of organisms happens to serve as a way station on one of the environmental pathways taken by a chemical or its transformation products. Gauging these pathways begins with an introduction to partitioning and advective transport. 

Part III of the book discusses different properties of fibers. Fiber properties ean be classified into primaiy and secondary properties. Primary properties are those that fibers must possess so they can be converted into useful products. Examples of primary properties are aspect ratio, strength, flexibility, cohesiveness, and uniformity. Secondary properties are those that are desirable and can improve consumer satisfaction with the end-products made from the fibers. Secondary properties include, but are not hmited to physical shape, density, modulus, elongation, elastic recovery, resilience, thermal properties, electrical properties, color and optical properties, moisture regain, resistance to chemical and environmental conditions, resistance to biological organisms, and resistance to insects. Chapter 14 provides an introduction to these primary and secondary properties. 

For these purposes also complex analytical tools have to be further developed and to be applied. This includes for example the broad introduction of compound specific isotope analyses in environmental investigations. Although analytical limitations hindered an uncomplicated launching of isotope analyses in environmental studies so far (as described in chapter 4.2), the usefulness of this analytical tool requires an intensive development of appropriate analytical procedures for a successful implementation of this technique in environmental sciences. Similarly, also pyrolysis as well as chemical degradation techniques are not well introduced in environmental analyses compared to other organic geochemical studies. 

Molecular diffusion is an inherent and ubiquitous mass transport process by which chemical species move within and between environment phases. All environmental mass transfer coefficients, in one way or another, reflect the molecular diffusivity of the chemical species in the environmental solvents (i.e., air, water, organic matter, nonaqueous liquids, solids, etc.). It is therefore the fundamental transport parameter for molecular mass transport. It is important to keep in mind that diffusion is generally only used to describe molecular motion in the absence of mechanical mixing or advection. The material in this chapter provides a brief, theoretical introduction to diffusivities and follows this with estimation techniques, developed using empirical data, for chemicals in the significant environmental media compartments. The chapter concludes with example calculations. 

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