Acid-base chemistry theories

Developments in equilibrium theory in the late nineteenth century led to significant improvements in the theoretical understanding of acid-base chemistry and. 

Up to this point, we have dealt with the subject of acid-base chemistry in terms of proton transfer. If we seek to learn what it is that makes NH3 a base that can accept a proton, we find that it is because there is an unshared pair of electrons on the nitrogen atom where the proton can attach. Conversely, it is the fact that the hydrogen ion seeks a center of negative charge that makes it leave an acid such as HC1 and attach to the ammonia molecule. In other words, it is the presence of an unshared pair of electrons on the base that results in proton transfer. Sometimes known as the electronic theory of acids and bases, this shows that the essential characteristics of acids and bases do not always depend on the transfer of a proton. This approach to acid-base chemistry was first developed by G. N. Lewis in the 1920s. 

Luder, W. F., and Zuffanti, S. (1946). The Electronic Theory of Acids and Bases. Wiley, New York. A small book that is a classic in Lewis acid-base chemistry. Also available as a reprint volume from Dover. 

In writing this book, I have attempted to produce a concise textbook that meets several objectives. First, the topics included were selected in order to provide essential information in the major areas of inorganic chemistry (molecular structure, acid-base chemistry, coordination chemistry, ligand field theory, solid state chemistry, etc.). These topics form the basis for competency in inorganic chemistry at a level commensurate with the one semester course taught at most colleges and universities. 

B Hess, Joule, Kelvin, and Gibbs all contributed to thermochemistry and have thermodynamic entities named after them. Volta, Faraday, and Galvani (choice D) contributed to electrochemistry, Kekule to organic chemistry, London to chemical bonding, Boyle and Charles to gas laws, Arrhenius to acid/base chemistry and thermochemstry, Pauli to quantum theory, Davy and Ramsay to element isolation, and Mendeleev to the periodic table. 

Refs. [i] Finston H, Rychtman AC (1982) A new view of current acid-base theories. Wiley, New York [ii] Hand CW, Blewitt HL (1986) Acid-base chemistry. Macmillan, New York... 

Acid-base chemistry was first satisfactorily explained in molecular terms after Ostwald and Arrhenius established the existence of ions in aqueous solution in 1880-1890 (after much controversy and professional difficulties, Arrhenius received the 1903 Nobel Prize in Chemistry for this theory). As defined at that time, Arrhenius adds form... 

Acid-Base Chemistry (Hard-Soft-Acid-Base Theory)... 

For aqueous solutions, the Bronsted-Lowry theory adequately describes the behavior of acids and bases. We shall limit our discussion of acid-base chemistry to aqueous solutions and use the following definitions ... 

A meticulous experimenter, Thomas Lowry is best known for his conceptualization of acid-base chemistry. Studies of nitrogenous compounds led Lowry to question fundamental aspects of the role of hydrogen during acid-base reactions. Three months before Br0nsted published his theory, Lowry released his own similar thoughts on proton acceptors and donors In print. 

Lewis made additional valuable contributions to the theory of colored substances, radiation, relativity, the separation of isotopes, heavy water, photochemistry, phosphorescence, and fluorescence. As a major in the U.S. Army Chemical Warfare Service during World War I, he worked on defense systems against poison gases. From 1922 to 1935 he was nominated numerous times for the Nobel Prize in chemistry. Lewis s death, while measuring the dielectric constant of hydrogen cyanide on March 23, 1946, precluded his receiving the prize, which is not awarded posthumously, see also Acid-Base Chemistry Lewis Structures. 

Chapter 1 reviews the topics from general chemistry that will be important to your study of organic chemistry. The chapter starts with a description of the structure of atoms and then proceeds to a description of the structure of molecules. Molecular orbital theory is introduced. Acid-base chemistry, which is central to understanding many organic reactions, is reviewed. You will see how the structure of a molecule affects its acidity and how the acidity of a solution affects molecular structure. 

In this chapter, we explain how the scientific understanding of acids and bases has changed through time. We start by explaining how to measure their strengths using the pH scale. We also explain the multiple theories of acid-base chemistry, from Lavoisier s first attempt to classify these materials, to the modern understanding of Lewis acids and bases. 

Lemery, Nicolas (1645-1715) French chemist, who was one of the first to develop theories on acid-base chemistry. 

So far, the emphasis has been on concept creation, roughly following the route of history. This brings us to around the eighteenth century. French chemist Nicolas Lemery (1645-1715) was born in Rouen and was one of the first scientists to develop theories on acid-base chemistry. By a theory, I mean a causal explanation that makes sense of all, or as much as possible, of the data that has been collected to date. The theory should be able to predict new information that can be collected and tested for compatibility. Earlier in this chapter I called this fertility . A theory of acidity should ej lain why all the members of the class of acids behave as they do and why the nonmembers do not. When chemists construct a theory, they may find that minor alterations are required. This is called accommodation and is felt to be natural in the development of a theory. If, however, there comes a point where accommodation cannot explain a large portion of the new evidence, a new explanation is created. This is called a paradigm shift and the topic of acidity offers examples of it that will be explored later. 

The Lewis theory, by virtue of its broader definition of acids, allows acid—base theory to include all of the Bronsted-Lowry reactions and, as we shall see, a great many others. Most of the reactions we shall study in organic chemistry involve Lewis acid—base interactions, and a sound understanding of Lewis acid—base chemistry will help greatly. 

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