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Hydrogen Electrolysis
Electrolysis of water, also known as electrochemical water splitting, is the process of using electricity to decompose water into oxygen and hydrogen gas by electrolysis. Hydrogen gas released in this way can be used as hydrogen fuel, or remixed with the oxygen to create oxyhydrogen gas, which is used in welding and other applications. Electrolysis of water requires a minimum potential difference of 1.23 volts, though at that voltage external heat is required. E lectrolysis is rarely used in industrial applications since hydrogen can be produced less expensively from fossil fuels. History In 1789, Jan Rudolph Deiman and Adriaan Paets van Troostwijk used an electrostatic machine to make electricity that was discharged on gold electrodes in a Leyden jar with water. In 1800 Alessandro Volta invented the voltaic pile, and a few weeks later English scientists William Nicholson and Anthony Carlisle used it to electrolyse water. In 1806 Humphry Davy reported the results of ext ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrolysis
In chemistry and manufacturing, electrolysis is a technique that uses direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. The voltage that is needed for electrolysis to occur is called the decomposition potential. The word "lysis" means to separate or break, so in terms, electrolysis would mean "breakdown via electricity". Etymology The word "electrolysis" was introduced by Michael Faraday in 1834, using the Greek words "amber", which since the 17th century was associated with electrical phenomena, and ' meaning "dissolution". Nevertheless, electrolysis, as a tool to study chemical reactions and obtain pure elements, precedes the coinage of the term and formal description by Faraday. History In the early nineteenth century, William Nicholson and Anthony Carlisle sought to further Volt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voltaic Pile
upright=1.2, Schematic diagram of a copper–zinc voltaic pile. The copper and zinc discs were separated by cardboard or felt spacers soaked in salt water (the electrolyte). Volta's original piles contained an additional zinc disk at the bottom, and an additional copper disk at the top. These were later shown to be unnecessary file:VoltaBattery.JPG, upA voltaic pile on display in the ''Tempio Voltiano'' (the Volta Temple) near Volta's home in Como, Italy The voltaic pile was the first electrical battery that could continuously provide an electric current to a circuit. It was invented by Italian chemist Alessandro Volta, who published his experiments in 1799. The voltaic pile then enabled a rapid series of other discoveries including the electrical decomposition (electrolysis) of water into oxygen and hydrogen by William Nicholson and Anthony Carlisle (1800) and the discovery or isolation of the chemical elements sodium (1807), potassium (1807), calcium (1808), boron (1808), b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cathode
A cathode is the electrode from which a conventional current leaves a polarized electrical device. This definition can be recalled by using the mnemonic ''CCD'' for ''Cathode Current Departs''. A conventional current describes the direction in which positive charges move. Electrons have a negative electrical charge, so the movement of electrons is opposite to that of the conventional current flow. Consequently, the mnemonic ''cathode current departs'' also means that electrons flow ''into'' the device's cathode from the external circuit. For example, the end of a household battery marked with a + (plus) is the cathode. The electrode through which conventional current flows the other way, into the device, is termed an anode. Charge flow Conventional current flows from cathode to anode outside of the cell or device (with electrons moving in the opposite direction), regardless of the cell or device type and operating mode. Cathode polarity with respect to the anode can be positive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iridium
Iridium is a chemical element with the symbol Ir and atomic number 77. A very hard, brittle, silvery-white transition metal of the platinum group, it is considered the second-densest naturally occurring metal (after osmium) with a density of as defined by experimental X-ray crystallography. It is one of the most corrosion-resistant metals, even at temperatures as high as . However, corrosion-resistance is not quantifiable in absolute terms; although only certain molten salts and halogens are corrosive to solid iridium, finely divided iridium dust is much more reactive and can be flammable, whereas gold dust is not flammable but can be attacked by substances that iridium resists, such as aqua regia. Iridium was discovered in 1803 among insoluble impurities in natural platinum. Smithson Tennant, the primary discoverer, named it after the Greek goddess Iris, personification of the rainbow, because of the striking and diverse colors of its salts. Iridium is one of the rarest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platinum
Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish , a diminutive of "silver". Platinum is a member of the platinum group of elements and group 10 of the periodic table of elements. It has six naturally occurring isotopes. It is one of the rarer elements in Earth's crust, with an average abundance of approximately 5 μg/kg. It occurs in some nickel and copper ores along with some native deposits, mostly in South Africa, which accounts for ~80% of the world production. Because of its scarcity in Earth's crust, only a few hundred tonnes are produced annually, and given its important uses, it is highly valuable and is a major precious metal commodity. Platinum is one of the least reactive metals. It has remarkable resistance to corrosion, even at high temperatures, and is therefore considered a noble metal. Consequent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrode
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte, a vacuum or air). Electrodes are essential parts of batteries that can consist of a variety of materials depending on the type of battery. The electrophore, invented by Johan Wilcke, was an early version of an electrode used to study static electricity. Anode and cathode in electrochemical cells Electrodes are an essential part of any battery. The first electrochemical battery made was devised by Alessandro Volta and was aptly named the Voltaic cell. This battery consisted of a stack of copper and zinc electrodes separated by brine-soaked paper disks. Due to fluctuation in the voltage provided by the voltaic cell it wasn't very practical. The first practical battery was invented in 1839 and named the Daniell cell after John Frederic Daniell. Still making use of the zinc–copper electrode combination. Since then many more batteries have be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saints Cyrill And Methodius
Cyril (born Constantine, 826–869) and Methodius (815–885) were two brothers and Byzantine Christian theologians and missionaries. For their work evangelizing the Slavs, they are known as the "Apostles to the Slavs". They are credited with devising the Glagolitic alphabet, the first alphabet used to transcribe Old Church Slavonic. After their deaths, their pupils continued their missionary work among other Slavs. Both brothers are venerated in the Eastern Orthodox Church as saints with the title of "equal-to-apostles". In 1880, Pope Leo XIII introduced their feast into the calendar of the Roman Catholic Church. In 1980, the first Slav pope, Pope John Paul II declared them co-patron saints of Europe, together with Benedict of Nursia. Apostolic letter of Pope John Paul II, 31 December 1980 Early career Early life The two brothers were born in Thessalonica, then located in the Byzantine province of the same name (today in Greece) – Cyril in about 827–828 and Methodius i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dmitry Lachinov
Dmitry Aleksandrovich Lachinov (russian: Дмитрий Александрович Лачи́нов ) (10 Jan 1842 – 15 October 1902) was a Russian physicist, electrical engineer, inventor, meteorologist and climatologist. Biography Dmitry Lachinov studied in the St. Petersburg University, where he was a pupil of Heinrich Lenz, Pafnuty Chebyshev and Feodor Petrushevsky. In 1862, when the University was closed because of the students' unrest, Lachinov went to Germany and for two and a half years studied there under the guidance of Gustav Kirchhoff, Robert Bunsen and Hermann Helmholtz, attending practical lessons in their laboratories in Heidelberg and Tübingen. In a paper released in 1880, Lachinov became the first one to point out the possibility of electricity transmission over long distances, and to propose the means of achieving it — 18 months before the first publication of the article with similar conclusions by Marcel Deprez. In 1889 Lachinov wrote the first textb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Production
Hydrogen production is the family of industrial methods for generating hydrogen gas. As of 2020, the majority of hydrogen (∼95%) is produced from fossil fuels by steam reforming of natural gas and other light hydrocarbons, partial oxidation of heavier hydrocarbons, and coal gasification. Other methods of hydrogen production include biomass gasification, zero-CO2-emission methane pyrolysis, and electrolysis of water. The latter processes, methane pyrolysis as well as water electrolysis can be done directly with any source of electricity, such as solar power. The production of hydrogen plays a key role in any industrialized society, since hydrogen is required for many essential chemical processes. In 2020, roughly 87 million tons of hydrogen was produced worldwide for various uses, such as oil refining, and in the production of ammonia (NH3) (through the Haber process) and methanol (CH3OH) (through reduction of carbon monoxide O, and also as a fuel in transportation. The glo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gramme Machine
A Gramme machine, Gramme ring, Gramme magneto, or Gramme dynamo is an electrical generator that produces direct current, named for its Belgian inventor, Zénobe Gramme, and was built as either a dynamo or a magneto. It was the first generator to produce power on a commercial scale for industry. Inspired by a machine invented by Antonio Pacinotti in 1860, Gramme was the developer of a new induced rotor in form of a wire-wrapped ring (Gramme ring) and demonstrated this apparatus to the Academy of Sciences in Paris in 1871. Although popular in 19th century electrical machines, the Gramme winding principle is no longer used since it makes inefficient use of the conductors. The portion of the winding on the interior of the ring cuts no flux and does not contribute to energy conversion in the machine. The winding requires twice the number of turns and twice the number of commutator bars as an equivalent drum-wound armature. Description The Gramme machine used a ring armature, with a se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zénobe Gramme
Zénobe Théophile Gramme (4 April 1826 – 20 January 1901) was a Belgian electrical engineer. He was born at Jehay-Bodegnée on 4 April 1826, the sixth child of Mathieu-Joseph Gramme, and died at Bois-Colombes on 20 January 1901. He invented the Gramme machine, a type of direct current dynamo capable of generating smoother (less AC) and much higher voltages than the dynamos known to that point. Career Gramme was poorly educated and semi-literate throughout his life. His talent was in handicraft and when he left school he became a joiner. After moving to Paris he took a job as a model maker at a company that manufactured electrical equipment and there became interested in technology. Having built an improved dynamo, Gramme, in association with Hippolyte Fontaine, opened a factory to develop the device. The business, called Société des Machines Magnéto-Électriques Gramme, manufactured the Gramme dynamo, Gramme ring, Gramme armature and other devices. In 1873 a Gramme dynam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitric Acid
Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nitric acid has a concentration of 68% in water. When the solution contains more than 86% , it is referred to as ''fuming nitric acid''. Depending on the amount of nitrogen dioxide present, fuming nitric acid is further characterized as red fuming nitric acid at concentrations above 86%, or white fuming nitric acid at concentrations above 95%. Nitric acid is the primary reagent used for nitration – the addition of a nitro group, typically to an organic molecule. While some resulting nitro compounds are shock- and thermally-sensitive explosives, a few are stable enough to be used in munitions and demolition, while others are still more stable and used as pigments in inks and dyes. Nitric acid is also commonly used as a strong oxidizing agen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
