Richter, Jeremias

The laws of definite and multiple proportions are also associated with Dalton, for they can be explained by his atomic hypothesis. The law of definite proportions or of constant composition had previously been proposed in the work of Jeremias Richter and Joseph-Louis Proust. The law of multiple proportions came to be regarded as an empirical law quite independent of its relation to the atomic hypothesis or perhaps as an empirical law that inspired the atomic hypothesis however, Roscoe and Harden have shown that in Dalton s mind it was a testable prediction which followed from the atomic hypothesis 4). 

Jeremias Benjamin Richter, der entdecker der chemischen pro-portionen, Breslau, 1874. 

The concept of stoichiometry was first described in 1792 by the German scientist Jeremias Benjamin Richter (1762-1807). He stated that "stoichiometry is the science of measuring the quantitative proportions or mass ratios in which chemical elements stand to one another." Can you think of another reason why Richter was famous ... 

In addition to Cavendish and Lavoisier a host of other workers had accumulated a mass of mathematical results. Wenzel had studied the effects of an acid like vinegar on a base like ammonia water. Later, Jeremias Richter found that they, like other acids and bases, combined in constant proportions and in 1794 he published his Foundations of Stoichiometry or Art of Measuring the Chemical Elements. It was from this hazy book that G. E. Fischer collected the data which enabled him to arrange a clear, simple table. This table was the key to Dalton s problem. 

Partington, James Riddick. Jeremias Benjamin Richter and the Law of Reciprocal Proportions. Ann. Sci. 7, 173-198 (1951). 

The idea of chemical equivalents was stated by Henry Cavendish in 1767, clarified by Jeremias Richter in 1795, and popularized by William Wollaston in 1814. Wollaston applied the concept to elements and defined it in such a way that one equivalent of an element corresponded to its atomic mass. Thus, when Wollaston s equivalent is expressed in grams, it is identical to a mole. It is not surprising then that the word mole is derived from molekulargewicht (German, meaning molecular weight ) and was coined in 1901 or 1902. see ALSO Avogadro, Amedeo Cannizzaro, Stanislao Cavendish, Henry Gay-Lussac, Joseph-Louis. 

The term stoichiometry was devised by German chemist Jeremias Richter in 1792 to describe the measnrement of the combining ratios of chemical elements by mass. The term has since been expanded to include the combining ratios of substances in any chemical reaction. Richter studied mathematics with philosopher Immanuel Kant and wrote a thesis on the nse of mathematics in chemistry. He was convinced that all chemical changes conld be described in terms of simple whole-number ratios. He put forward the Law of Reciprocal Proportions, stating that if two chemical elements unite separately with a third element, the proportion in which they unite with the third element will be the same or a multiple of the proportion in which they unite with each other. This law has disappeared from most chemistry textbooks, but a companion law, the Law of Multiple Proportions, has survived. 

This equation serves to identify the species taking part and shows that for every two H2 molecules and one O2 molecule that react, two molecules of water are formed. This information concerning the relative amounts of reactants and products is known as the stoichiometry of the reaction. This term was introduced by the German chemist Jeremias Benjamin Richter as early as 1792 in order to denote the relative amounts in which acids and bases neutralize each other it is now used in a more general way. 

Jeremias Benjamin Richter, bom Mar. 10, 1762, in Hrrschberg, now Jelenia Gora, Poland, died Apr. 14, 1807, in Berlin, Germany. 

A forerunner of Dalton, Jeremias Benjamin Richter (a porcelain chemist who died of tuberculosis at the age of 45) had proposed that chemical processes are based on mathematical laws, and he had coined... 

FIGURE 3.2 Jeremias Benjamin Richter (1762-1807), the originator of the term stoichiometry. This image is in the public domain, and it was obtained from http //commons. wikimedia... 

Quantitative results of a different kind were obtained by Jeremias Richter (1762-1807). He was obsessed with obtaining mathematical relationships in chemistry, and he helped to establish the concept of equivalent or combining weight. His work was summarised in 1802 by Ernst Fischer (1754-1831), who produced a table of equivalent weights of acids and bases related to sulphuric acid having a value of 1000. On this scale, muriatic acid (HCl) had a value of 712, and soda and potash had values of 859 and 1605 respectively. This meant that 859 parts of soda or 1605 parts of potash were required to neutralise 1000 parts of sulphuric acid or 712 parts of muriatic acid. 

Jeremias Benjamin Richters particle size explanation for the color of drinkable gold colloidal gold known since antiquity (e.g., Lycurgus cup, fourth century AD)... 

German chemist Jeremias Richter studies the mass ratios... 

The basis for the elaboration of this dynamist chemistry was provided by the sensible qualities of chemical substances. The explanation supposed that matter was animated by forces — magnetic, electric, chemical — with opposite polarities responsible for the phenomenal quahties of the matter. This treatment of qualities was inspired by Kant s notion of intensive quantity that he proposed in his Metaphysical Foundations of Natural Science from 1786. In contrast to form and motion, intensive quantities are not amenable to mathematical representation, but can nevertheless be handled quantitatively as non-additive quantities. The science of stoichiometry developed by Jeremias Richter (1762—1807) (one of Kant s students) illustrates this approach nicely. Wanting to introduce a mathematical approach to experimental chemistry, Richter quantified the properties of being acidic or basic by placing them on a scale, thereby allowing him to determine the proportions of the reactants involved in the formation of salts, leading to his proposal of the law of neutralization. 

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