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Jeremias Richter
Jeremias Benjamin Richter (; 10 March 1762 – 4 May 1807) was a German chemist. He was born at Hirschberg in Silesia, became a mining official at Breslau in 1794, and in 1800 was appointed assessor to the department of mines and chemist to the royal porcelain factory at Berlin, where he died. He is known for introducing the term ''stoichiometry''. Developer of titration He made some of the earliest known determinations of the quantities by weight in which acids saturate bases and bases acids. He realised that those amounts of different bases which can saturate the same quantity of a particular acid are equivalent to each other (see ''Titration''). He was thus led to conclude that chemistry is a branch of applied mathematics and to endeavour to trace a law according to which the quantities of different bases required to saturate a given acid formed an arithmetical progression, and the quantities of acids saturating a given base a geometric progression. Law of definite propor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jelenia Góra
Jelenia Góra (pron. ; Polish: ; german: Hirschberg im Riesengebirge; Exonym: ''Deer Mountain''; szl, Jelyniŏ Gōra) is a historic city in southwestern Poland, within the historical region of Lower Silesia. Jelenia Góra is situated in the Lower Silesian Voivodeship, close to the Karkonosze mountain range running along the Polish-Czech border – ski resorts such as Karpacz and Szklarska Poręba are situated from the city. Jelenia Góra constitutes a separate urban gmina as well as being the seat of surrounding Karkonosze County (formerly Jelenia Góra County). In 2021 the population of Jelenia Góra was 77,366. The area, including the oldest spa district of Cieplice Śląskie-Zdrój, is one of the most valued recreational and leisure spots in Poland. The city's history dates back to as early as the 10th century, but the settlement was granted town rights under Polish rule in 1288. Jelenia Góra was founded on important trade routes linking the Holy Roman Empire and Bohemia w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geometric Progression
In mathematics, a geometric progression, also known as a geometric sequence, is a sequence of non-zero numbers where each term after the first is found by multiplying the previous one by a fixed, non-zero number called the ''common ratio''. For example, the sequence 2, 6, 18, 54, ... is a geometric progression with common ratio 3. Similarly 10, 5, 2.5, 1.25, ... is a geometric sequence with common ratio 1/2. Examples of a geometric sequence are powers ''r''''k'' of a fixed non-zero number ''r'', such as 2''k'' and 3''k''. The general form of a geometric sequence is :a,\ ar,\ ar^2,\ ar^3,\ ar^4,\ \ldots where ''r'' ≠ 0 is the common ratio and ''a'' ≠ 0 is a scale factor, equal to the sequence's start value. The sum of a geometric progression terms is called a ''geometric series''. Elementary properties The ''n''-th term of a geometric sequence with initial value ''a'' = ''a''1 and common ratio ''r'' is given by :a_n = a\,r^, and in general :a_n = a_m\,r^. Such a geometric ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1762 Births
Year 176 ( CLXXVI) was a leap year starting on Sunday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Proculus and Aper (or, less frequently, year 929 ''Ab urbe condita''). The denomination 176 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * November 27 – Emperor Marcus Aurelius grants his son Commodus the rank of ''Imperator'', and makes him Supreme Commander of the Roman legions. * December 23 – Marcus Aurelius and Commodus enter Rome after a campaign north of the Alps, and receive a triumph for their victories over the Germanic tribes. * The Equestrian Statue of Marcus Aurelius is made. It is now kept at Museo Capitolini in Rome (approximate date). Births * Fa Zheng, Chinese nobleman and adviser (d. 220) * Liu Bian, Chinese emperor of the Han Dynasty ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equivalent Weight
In chemistry, equivalent weight (also known as gram equivalent) is the mass of one equivalent, that is the mass of a given substance which will combine with or displace a fixed quantity of another substance. The equivalent weight of an element is the mass which combines with or displaces 1.008 gram of hydrogen or 8.0 grams of oxygen or 35.5 grams of chlorine. These values correspond to the atomic weight divided by the usual valence; for oxygen as example that is 16.0 g / 2 = 8.0 g. For acid–base reactions, the equivalent weight of an acid or base is the mass which supplies or reacts with one mole of hydrogen cations (). For redox reactions, the equivalent weight of each reactant supplies or reacts with one mole of electrons (e−) in a redox reaction. Equivalent weight has the units of mass, unlike atomic weight, which is now used as a synonym for relative atomic mass and is dimensionless. Equivalent weights were originally determined by experiment, but (insofar as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germain Henri Hess
Germain Henri Hess (russian: Герман Иванович Гесс, German Ivanovich Gess; 7 August 1802 – 30 November 1850) was a Swiss-Russian chemist and doctor who formulated Hess's law, an early principle of thermochemistry. Early life and education Hess was born on 26 July (7 August) in Geneva, Switzerland. His father was an artist and in 1805 moved the family to Russia to work as a tutor to a rich family. His Swiss-born mother was a tutor as well and Hess had the benefit of learning German and French at home. In 1817, his family moved to Dorpat, Russian Empire (now Tartu, Estonia), where he went to a private school for two years, and then to Dorpat Gymnasium, which he finished in 1822. In autumn of the same year Hess studied medicine at the University of Dorpat. During that time, the chemistry department was responsible for the Chemistry courses of the Medicine and Pharmacy departments and Professor Gottfried W. Osann was giving the lectures in German (an obvious ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Friedrich Wenzel
Carl Friedrich Wenzel (February 26, 1793) was a German chemist and metallurgist who determined the reaction rates of various chemicals, establishing, for example, that the amount of metal that dissolves in an acid is proportional to the concentration of acid in the solution. Thus he was the first person to give the notion of equivalent weight and to publish a table of equivalent weights of acids and bases. Later Jeremias Benjamin Richter produced a larger table of equivalent weights. Wenzel, whose first name is also spelled Karl, was born at Dresden in 1740. Disliking his father's trade of bookbinding, for which he was intended, he left home in 1755, and after taking lessons in surgery and chemistry at Amsterdam, became a ship's surgeon in the Dutch service. In 1766, tired of sea-life, he went to study chemistry at Leipzig, and afterwards devoted himself to metallurgy and assaying at his native place with much success. Thanks to that success, in 1780 Wenzel was appointed chemist t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Law Of Definite Proportions
In chemistry, the law of definite proportions, sometimes called Proust's law, or law of constant composition states that a given chemical compound always contains its component elements in fixed ratio (by mass) and does not depend on its source and method of preparation. For example, oxygen makes up about 8/9 of the mass of any sample of pure water, while hydrogen makes up the remaining 1/9 of the mass: the mass of two elements in a compound are always in the same ratio. Along with the law of multiple proportions, the law of definite proportions forms the basis of stoichiometry. History The law of constant proportion was given by Joseph Proust in 1797. This observation was first made by the English theologian and chemist Joseph Priestley, and Antoine Lavoisier, a French nobleman and chemist centered on the process of combustion. The law of definite proportions might seem obvious to the modern chemist, inherent in the very definition of a chemical compound. At the end of the 18 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph Proust
Joseph Louis Proust (26 September 1754 – 5 July 1826) was a French chemist. He was best known for his discovery of the law of definite proportions in 1794, stating that chemical compounds always combine in constant proportions. Life Joseph L. Proust was born on September 26, 1754, in Angers, France. His father served as an apothecary in Angers. Joseph studied chemistry in his father's shop and later went to Paris where he gained the appointment of apothecary in chief to the Salpêtrière. He also taught chemistry with Pilâtre de Rozier, a famous aeronaut. Under Carlos IV's influence Proust went to Spain. There he taught at the Chemistry School in Segovia and at the University of Salamanca. But when Napoleon invaded Spain, they burned Proust's laboratory and forced him back to France. On July 5, 1826, he died in Angers, France. The mineral proustite (Ag3AsS3) is named in his honour. Chemistry studies Proust's largest accomplishment in the realm of science was disproving Ber ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A History Of European Thought In The Nineteenth Century
A, or a, is the first letter and the first vowel of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''a'' (pronounced ), plural ''aes''. It is similar in shape to the Ancient Greek letter alpha, from which it derives. The uppercase version consists of the two slanting sides of a triangle, crossed in the middle by a horizontal bar. The lowercase version can be written in two forms: the double-storey a and single-storey ɑ. The latter is commonly used in handwriting and fonts based on it, especially fonts intended to be read by children, and is also found in italic type. In English grammar, " a", and its variant " an", are indefinite articles. History The earliest certain ancestor of "A" is aleph (also written 'aleph), the first letter of the Phoenician alphabet, which consisted entirely of consonants (for that reason, it is also called an abjad to distinguish it f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Theodore Merz
John Theodore Merz (30 March 1840 – 21 March 1922) was a German British chemist, historian and industrialist. Merz was born in Manchester, England and educated at University of Giessen, Göttingen, Heidelberg, and Bonn universities. Merz was vice-chairman of the Newcastle-upon-Tyne Electric Supply Company, which he founded in 1889. He was chairman of the Tyneside Tramways and Tramroads Company and a member of the senate of Durham University. In 1906, he was awarded an LLD degree from the University of Aberdeen. The author of philosophical works on Leibniz, and ''Religion and Science'' (1915), his four volume ''History of European Thought in the Nineteenth Century'' consummated William Whewell's ''History of the Inductive Sciences'' (1837) and ''The Philosophy of the Inductive Sciences, Founded Upon Their History'' (1840) as well as William Stanley Jevons William Stanley Jevons (; 1 September 183513 August 1882) was an English economist and logician. Irving Fisher d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
