Electrochemistry nineteenth century

Friedrich Wilhelm Ostwald (1853-1932 Nobel prize, 1909) in 1886 gave in his textbook a description of the state-of-art of electrochemistry at the end of the nineteenth century. 

Two very important fields of natural science—chemistry and the science of electricity— matured and grew vigorously during the first half of the nineteenth century. Electrochemistry developed simultaneously. From the very beginning, electrochemistry was not merely a peripheral field but evolved with an important degree of independence, and it also left very significant marks on the development of chemistry and of the theory of electricity. 

The pursuit of chemical thermodynamics, especially its applications in solution chemistry and electrochemistry, resulted in the establishment of a distinct scientific discipline of physical chemistry by the so-called Ionists in the late nineteenth century. These practitioners defined their aim as "theoretical chemistry," bridging the domains of physics and chemistry. Ostwald contrasted the aims and methods of the new discipline with the practices of organic chemists, whom he characterized as powerful, hidebound, fact-mongering opponents of the young band of Ionists. 

Ostwald, the late-nineteenth-century co-founder of modern physical chemistry, claimed that physical chemistry is the descendant of Humphry Davy s and Michael Faraday s work in electrochemistry at the beginning of the cen-... 

Sorensen is usually considered to be the first to have realized the importance of hydrogen ion concentration in cells and in the solutions in which the properties of cell components were to be studied. He is also credited with the introduction of the pH scale. Electrochemistry started at the end of the nineteenth century. By 1909, Sorensen had introduced a series of dyes whose color changes were related to the pH of the solution, which was determined by the H+ electrode. The dyes were salts of weak acids or weak bases. He also devised simple methods for preparing phosphate buffer solutions covering the pH range 6-8. Eventually buffers and indicators were provided covering virtually the whole pH range. 

Although organic electrochemistry had already been established in the nineteenth century, only the 1960s saw the advent of detailed electroorganic mechanistic studies. 

When it was first isolated, aluminum was a rare and expensive metal. During the nineteenth century, it so symbolized modern technology that the Washington Monument was given an expensive aluminum tip. That rarity and expense was transformed by electrochemistry. Aluminum metal is now obtained on a huge scale by the Hall process. In 1886,... 

J. Thompson, 1893) and the development of chemical thermodynamics (G. N. Lewis, 1923). Building on this foundation, the utilization of electrochemical phenomena for thermodynamic characterization and analysis of molecules and ions (electroanalytical chemistry) began at the beginning of this century [po-tentiometry (1920) and polarography (1930)]. Relationships that describe the techniques of potentiometry and polarography derive directly from solution thermodynamics. In the case of polarography, there is a further dependence on the diffusion of ionic species in solution. The latter is the basis of conductivity measurements, another area that traces its origin to the nineteenth century. These quantitative relationships make it possible to apply electrochemistry to... 

Although this has been known since the very beginning of electrochemistry in the nineteenth century, commercial electroanalytical instrumentation has been available only for the past 35 years. The direct reduction of 02 in aqueous solutions (especially biological and water treatment and sewage samples) is... 

Nernst equation — A fundamental equation in -> electrochemistry derived by - Nernst at the end of the nineteenth century assuming an osmotic equilibrium between the metal and solution phases (- Nernst equilibrium). This equation describes the dependence of the equilibrium electrode - potential on the composition of the contacting phases. The Nernst equation can be derived from the - potential of the cell reaction (Ecen = AG/nF) where AG is the - Gibbs energy change of the - cell reaction, n is the charge number of the electrochemical cell reaction, and F is the - Faraday constant. 

Several famous equations (Einstein, Stokes-Einstein, Nemst-Einstein, Nernst-Planck) are presented in this chapter. They derive from the heyday of phenomenological physical chemistry, when physical chemists were moving from the predominantly thermodynamic approach current at the end of the nineteenth century to the molecular approach that has characterized electrochemistry in this century. The equations were originated by Stokes and Nernst but the names of Einstein and Planck have been added, presumably because these scientists had examined and discussed the equations first suggested by the other men. 

In parallel to inorganic an4 organic chemistry, physical chemistry 4evelope4 greatly in the nineteenth century. The three major fiel4s of progress were chemical kinetics, thermo4ynamics an4 electrochemistry. 

Electrochemistry begins with electrolysis. Practical and theoretical studies have already been conducted in early years of the nineteenth century. 

The electrochemical cell, or battery, enabled advances in many areas of research and development involving electricity during the nineteenth century including electrochemistry, electrophysiology, and the use of electricity as medical therapy. 

At the beginning of the nineteenth century, the British chemist Davy first prepared alkali metal-ammonia solutions. Davy was also the first person to make alkali metals using electrochemistry. Ammonia condenses at -33.35°C and becomes solid at -77.7°C. Alkali and some other metals dissolve readily in anhydrous ammonia solutions. Already in 1908, on the basis of conductivity measurements, Kraus proposed that alkali ions A+ exist in ammonia together with cavities containing a single electron (solvated electrons), in equilibrium with dissolved alkali metal atoms. At not too high concentration, alkali solutions are all deep blue, suggesting that the color arises from the electron cavities rather than directly from the metal ion. 

English physicist Michael Faraday, with only a few years of rudimentary education, later formulated the basic laws of electrochemistry and became the greatest experimental physicist of the nineteenth century. 

The absolute potentials of single electrodes have been a subject of interest since Ostwald, Nernst, and their contemporaries formulated the beginnings of modern electrochemistry in the nineteenth century. The twentieth century brought new methods of applying electrochemical measurements to analytical problems. For these, a knowledge of electrode potentials, or, alternatively, the activities of individual species of ions, could provide simplicity and accuracy not hitherto attainable. Nevertheless, ordinary thermodynamic procedures are incapable of measuring these quantities. 

If the current generated by one of the anodic reactions expressed earlier was known, it would be possible to convert this current to an equivalent mass loss or corrosion penetration rate with a very useful relation discovered by Michael Faraday, a nineteenth century pioneer in electrochemistry. Faraday s empirical laws of electrolysis relate the current of an electrochemical reaction to the number of moles of the element being reacted and the number of moles of electrons involved. Supposing that the charge required for such reaction was one electron per molecule, as is the case for the plating or the corrosion attack of silver described respectively in Eqs. (3.11) and (3.12) ... 

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