Chemical substances properties

Chemical Substances Properties Toxicology Ecotoxicology Underway (R=Recommended)... 

List of 22 data bases to calculate physical and chemical substance properties. 

Relatively simple notions of attractive forces between opposite charges are suffi cient to account for many of the properties of chemical substances You will find it help ful to keep the polarity of carbon-oxygen and carbon-halogen bonds m mind as we develop the properties of alcohols and alkyl halides m later sections... 

References D. D. Wagman, et ah, The NBS Tables of Chemical Thermodynamic Properties, in J. Phys. Chem. Ref. Data, 11 2,1982 M. W. Chase, et ah, JANAF Thermochemical Tables, 3rd ed., American Chemical Society and the American Institute of Physics, 1986 (supplements to JANAF appear in J. Phys. Chem. Ref. Data) Thermodynamic Research Center, TRC Thermodynamic Tables, Texas A M University, College Station, Texas I. Barin and O. Knacke, Thermochemical Properties of Inorganic Substances, Springer-Verlag, Berlin, 1973 J. B. Pedley, R. D. Naylor, and S. P. Kirby, Thermochemical Data of Organic Compounds, 2nd ed.. Chapman and Hall, London, 1986 V. Majer and V. Svoboda, Enthalpies of Vaporization of Organic Compounds, International Union of Pure and Applied Chemistry, Chemical Data Series No. 32, Blackwell, Oxford, 1985. 

JANAE U.S. Department of Commerce National Institute of Standards and Technology chemical thermodynamic properties of inorganic substances and of organic substances containing only one or two carbon atoms... 

A significant advantage of the PLM is in the differentiation and recognition of various forms of the same chemical substance polymorphic forms, eg, brookite, mtile, and anatase, three forms of titanium dioxide calcite, aragonite and vaterite, all forms of calcium carbonate Eorms I, II, III, and IV of HMX (a high explosive), etc. This is an important appHcation because most elements and compounds possess different crystal forms with very different physical properties. PLM is the only instmment mandated by the U.S. Environmental Protection Agency (EPA) for the detection and identification of the six forms of asbestos (qv) and other fibers in bulk samples. 

Many countries have adopted chemical substance iaventories ia order to monitor use and evaluate exposure potential and consequences. In the case of essential oils used in many fragrance appHcations, these oils must be on many of these Hsts. New essential oils used in fragrances are subject to premanufactuting or premarketing notification (PMN). PMN requirements vary by country and predicted volume of production. They require assessment of environmental and human health-related properties, and reporting results to designated governmental authorities. 

D. D. Wagman and co-workers. The NBS Tables of Chemical Thermodynamic Properties Selected Valuesfor Inorganic and and C Organic Substances in SI Units, in /. Phys. Chem. Ref. Data, 11, suppl. 2 (1982) M. W. Chase, Jr. and co-sso-rkers, JMNAF Thermochemical Tables, 3rd ed.. Part II, in /. Phys. 

American Conference of Governmental Industrial Hygienists, Threshold Timit Values for Chemical Substances in Workroom Air Adopted bjACGIHfor 1978 reprinted in N. I. Sax, Dangerous Properties of Industrial Materials 5th ed.. Van Nostrand Reinhold, New York, 1979, p. 12. 

The values given in the following table for the heats and free energies of formation of inorganic compounds are derived from a) Bichowsky and Rossini, Thermochemistry of the Chemical Substances, Reinhold, New York, 1936 (h) Latimer, Oxidation States of the Elements and Their Potentials in Aqueous Solution, Prentice-Hall, New York, 1938 (c) the tables of the American Petroleum Institute Research Project 44 at the National Bureau of Standards and (d) the tables of Selected Values of Chemical Thermodynamic Properties of the National Bureau of Standards. The reader is referred to the preceding books and tables for additional details as to methods of calculation, standard states, and so on. 

P. Patniak, A Comprehensive Guide to the Hazardous Properties of Chemical Substances, 2nd Edn, J. Wiley Sons, 1999. ISBN 0471291757. 

The authors have written and revised six chapters that describe the aspects of purificatton and properties of chemical substances. In addition to detailing physical method and procedures such as crystallization, distillation, chromatography, etc, the authors also address chemical methods and procedure used in purification Including conv sion to specific derivatives or complexes and regeneration of the original material in a much-purified form. 

The material in this section is divided into three parts. The first subsection deals with the general characteristics of chemical substances. The second subsection is concerned with the chemistry of petroleum it contains a brief review of the nature, composition, and chemical constituents of crude oil and natural gases. The final subsection touches upon selected topics in physical chemistry, including ideal gas behavior, the phase rule and its applications, physical properties of pure substances, ideal solution behavior in binary and multicomponent systems, standard heats of reaction, and combustion of fuels. Examples are provided to illustrate fundamental ideas and principles. Nevertheless, the reader is urged to refer to the recommended bibliography [47-52] or other standard textbooks to obtain a clearer understanding of the subject material. Topics not covered here owing to limitations of space may be readily found in appropriate technical literature. 

If physiology is concerned with the function, anatomy with the structure, and biochemistry with the chemistry of the living body, then pharmacology is concerned with the changes in function, structure, and chemical properties of the body brought about by chemical substances. 

The thermodynamic properties of a chemical substance are dependent upon its state and, therefore, it is important to indicate conditions when writing chemical reactions. For example, in the burning of methane to form carbon dioxide and water, it is important to specify whether each reactant and product are solid, liquid, or gaseous since different changes in the thermodynamic property will occur depending upon the state of each substance. Thus, different volume and energy changes occur in the reactions... 

The notion of a pnre chemical snbstance can be related to empirically identifiable properties (e.g. sharp melting and boiling temperatures) but is nowadays understood in theoretical terms that are abstract (Johnson, 2002 Taber, 2002a). So hydrogen, methane, diamond, sodium, sodium chloride and polythene - poly(ethene) - are all considered examples of single chemical substances, although they are very different... 

The knowledge that allows chemists to describe, interpret, and predict the behavior of chemical substances is gained by making careful experimental measurements. The properties of a sample can be divided into physical properties, which can be measured without observing a chemical reaction, and chemical properties, which are displayed only during a chemical transformation. Physical properties include familiar attributes such as size, color, and mass. Some chemical properties also are familiar to us. As examples, bleach reacts chemically with many colored substances to destroy their colors, and molecular oxygen reacts chemically with many fuels to generate heat. 

In the early days of chemistry, the list of known compounds was short, so chemists could memorize the names of all of them. New compounds were often named for their place of origin, physical appearance, or properties. As the science of chemistry grew, the number of known compounds increased quickly. Soon, nobody could keep track of all of the common names. Today, more than 20 million compounds are known, and thousands of new ones are discovered or created each year. Consequently, chemists need systematic procedures for naming chemical compounds. The International Union of Pure and Applied Chemistry (lUPAC) has established uniform guidelines for naming various types of chemical substances, and chemists increasingly use lUPAC-approved names rather than their common counterparts. Systematic names are less colorful than common names, but they make chemistry less hectic because it is much easier to learn a few systematic guidelines than to memorize the names of thousands of individual compounds. 

Siik is just one exampie of macromoiecuies, aiso known as poiymers. Macromoiecuies are the subject of this chapter. The principies introduced in Chapters 9-11 help to explain the properties of these molecules, many of which are carbon-based. In this chapter, we outline the principles of the stmcture and synthesis of the major classes of macromoiecuies and describe the properties that give these chemical substances central roles in industrial chemistry and biochemistry. We describe the components from which macromoiecuies are constmcted, some important industrial polymers, and the macromoiecuies found in living systems. 

The reason for this varied behaviour is not difficult to find. A population of bacteria does not possess the uniformity of properties inherent in pure chemical substances. This fact, together with the varied manner in which bactericides exert their effect and the complex nature of the bacterial cell, should provide adequate and satisfying reasons why the precise theories of reaction kinetics should have failed to explain the disinfeclion process. 

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