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Chlorine Gas
Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is a yellow-green gas at room temperature. It is an extremely reactive element and a strong oxidising agent: among the elements, it has the highest electron affinity and the third-highest electronegativity on the revised Pauling scale, behind only oxygen and fluorine. Chlorine played an important role in the experiments conducted by medieval alchemists, which commonly involved the heating of chloride salts like ammonium chloride (sal ammoniac) and sodium chloride ( common salt), producing various chemical substances containing chlorine such as hydrogen chloride, mercury(II) chloride (corrosive sublimate), and hydrochloric acid (in the form of ). However, the nature of free chlorine gas as a separate substance was only recognised around 1630 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Element
A chemical element is a species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species. Unlike chemical compounds, chemical elements cannot be broken down into simpler substances by any chemical reaction. The number of protons in the nucleus is the defining property of an element, and is referred to as its atomic number (represented by the symbol ''Z'') – all atoms with the same atomic number are atoms of the same element. Almost all of the baryonic matter of the universe is composed of chemical elements (among rare exceptions are neutron stars). When different elements undergo chemical reactions, atoms are rearranged into new compounds held together by chemical bonds. Only a minority of elements, such as silver and gold, are found uncombined as relatively pure native element minerals. Nearly all other naturally occurring elements occur in the Earth as compounds or mixtures. Air is primarily a mixture o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Chloride
The compound hydrogen chloride has the chemical formula and as such is a hydrogen halide. At room temperature, it is a colourless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hydrogen chloride gas and hydrochloric acid are important in technology and industry. Hydrochloric acid, the aqueous solution of hydrogen chloride, is also commonly given the formula HCl. Reactions Hydrogen chloride is a diatomic molecule, consisting of a hydrogen atom H and a chlorine atom Cl connected by a polar covalent bond. The chlorine atom is much more electronegative than the hydrogen atom, which makes this bond polar. Consequently, the molecule has a large dipole moment with a negative partial charge (δ−) at the chlorine atom and a positive partial charge (δ+) at the hydrogen atom. In part because of its high polarity, HCl is very soluble in water (and in other polar solvents). Upon contact, and HCl combine to form hydronium cations and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlor-alkali
The chloralkali process (also chlor-alkali and chlor alkali) is an industrial process for the electrolysis of sodium chloride (NaCl) solutions. It is the technology used to produce chlorine and sodium hydroxide (caustic soda), which are commodity chemicals required by industry. Thirty five million tons of chlorine were prepared by this process in 1987. The chlorine and sodium hydroxide produced in this process are widely used in the chemical industry. Usually the process is conducted on a brine (an aqueous solution of NaCl), in which case sodium hydroxide (NaOH), hydrogen, and chlorine result. When using calcium chloride or potassium chloride, the products contain calcium or potassium instead of sodium. Related processes are known that use molten NaCl to give chlorine and sodium metal or condensed hydrogen chloride to give hydrogen and chlorine. The process has a high energy consumption, for example around of electricity per tonne of sodium hydroxide produced. Because the pr ... [...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] |
Brine
Brine is a high-concentration solution of salt (NaCl) in water (H2O). In diverse contexts, ''brine'' may refer to the salt solutions ranging from about 3.5% (a typical concentration of seawater, on the lower end of that of solutions used for brining foods) up to about 26% (a typical saturated solution, depending on temperature). Brine forms naturally due to evaporation of ground saline water but it is also generated in the mining of sodium chloride. Brine is used for food processing and cooking (pickling and brining), for de-icing of roads and other structures, and in a number of technological processes. It is also a by-product of many industrial processes, such as desalination, so it requires wastewater treatment for proper disposal or further utilization (fresh water recovery). In nature Brines are produced in multiple ways in nature. Modification of seawater via evaporation results in the concentration of salts in the residual fluid, a characteristic geologic deposit call ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abundance Of Elements In Earth's Crust
The abundance of elements in Earth's crust is shown in tabulated form with the estimated crustal abundance for each chemical element shown as mg/kg, or parts per million (ppm) by mass (10,000 ppm = 1%). Estimates of elemental abundance are difficult because (a) the composition of the upper and lower crust are quite different, and (b) the composition of the continental crust can vary drastically by locality. David KringComposition of Earth's continental crust as inferred from the compositions of impact melt sheets Lunar and Planetary Science XXVIII List of abundance by element See also * Abundances of the elements (data page) * Atmospheric chemistry * Clarke number — lists of historical data and terminology * List of chemical elements This is a list of the 118 chemical elements which have been identified as of 2022. A chemical element, often simply called an element, is a type of atom which has the same number of protons in its atomic nucleus (i.e., the same atomic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloride
The chloride ion is the anion (negatively charged ion) Cl−. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as hydrogen chloride is dissolved in water or other polar solvents. Chloride salts such as sodium chloride are often very soluble in water.Green, John, and Sadru Damji. "Chapter 3." ''Chemistry''. Camberwell, Vic.: IBID, 2001. Print. It is an essential electrolyte located in all body fluids responsible for maintaining acid/base balance, transmitting nerve impulses and regulating liquid flow in and out of cells. Less frequently, the word ''chloride'' may also form part of the "common" name of chemical compounds in which one or more chlorine atoms are covalently bonded. For example, methyl chloride, with the standard name chloromethane (see IUPAC books) is an organic compound with a covalent C−Cl bond in which the chlorine is not an anion. Electronic properties A chloride ion (diameter 167 pm) is much larger tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Greek Language
Ancient Greek includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek Dark Ages, Dark Ages (), the Archaic Greece, Archaic period (), and the Classical Greece, Classical period (). Ancient Greek was the language of Homer and of fifth-century Athens, fifth-century Athenian historians, playwrights, and Ancient Greek philosophy, philosophers. It has contributed many words to English vocabulary and has been a standard subject of study in educational institutions of the Western world since the Renaissance. This article primarily contains information about the Homeric Greek, Epic and Classical periods of the language. From the Hellenistic period (), Ancient Greek was followed by Koine Greek, which is regarded as a separate historical stage, although its earliest form closely resembles Attic Greek and its latest form a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sir Humphry Davy
Sir Humphry Davy, 1st Baronet, (17 December 177829 May 1829) was a British chemist and inventor who invented the Davy lamp and a very early form of arc lamp. He is also remembered for isolating, by using electricity, several elements for the first time: potassium and sodium in 1807 and calcium, strontium, barium, magnesium and boron the following year, as well as for discovering the elemental nature of chlorine and iodine. Davy also studied the forces involved in these separations, inventing the new field of electrochemistry. Davy is also credited to have been the first to discover clathrate hydrates in his lab. In 1799 he experimented with nitrous oxide and was astonished at how it made him laugh, so he nicknamed it "laughing gas" and wrote about its potential anaesthetic properties in relieving pain during surgery. Davy was a baronet, President of the Royal Society (PRS), Member of the Royal Irish Academy (MRIA), Fellow of the Geological Society (FGS), and a member of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxide
An oxide () is a chemical compound that contains at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion of oxygen, an O2– (molecular) ion. with oxygen in the oxidation state of −2. Most of the Earth's crust consists of oxides. Even materials considered pure elements often develop an oxide coating. For example, aluminium foil develops a thin skin of Al2O3 (called a passivation layer) that protects the foil from further corrosion.Greenwood, N. N.; & Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford:Butterworth-Heinemann. . Stoichiometry (the measurable relationship between reactants and chemical equations of a equation or reaction) Oxides are extraordinarily diverse in terms of stoichiometries and in terms of the structures of each stoichiometry. Most elements form oxides of more than one stoichiometry. A well known example is carbon monoxide and carbon dioxide.Greenwood, N. N.; & Earnshaw, A. (1997). Chemistry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Wilhelm Scheele
Carl Wilhelm Scheele (, ; 9 December 1742 – 21 May 1786) was a Swedish German pharmaceutical chemist. Scheele discovered oxygen (although Joseph Priestley published his findings first), and identified molybdenum, tungsten, barium, hydrogen, and chlorine, among others. Scheele discovered organic acids tartaric, oxalic, uric, lactic, and citric, as well as hydrofluoric, hydrocyanic, and arsenic acids. He preferred speaking German to Swedish his whole life, as German was commonly spoken among Swedish pharmacists.Fors, Hjalmar 2008. Stepping through Science’s Door: C. W. Scheele, from Pharmacist's Apprentice to Man of Science. Ambix 55: 29–49 Biography Scheele was born in Stralsund, in western Pomerania, which at the time was a Swedish Dominion inside the Holy Roman Empire. Scheele's father, Joachim (or Johann) Christian Scheele, was a grain dealer and brewer from a respected Pomeranian family. His mother was Margaretha Eleanore Warnekros. Friends of Scheele's pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jan Baptist Van Helmont
Jan Baptist van Helmont (; ; 12 January 1580 – 30 December 1644) was a chemist, physiologist, and physician from Brussels. He worked during the years just after Paracelsus and the rise of iatrochemistry, and is sometimes considered to be "the founder of pneumatic chemistry". Van Helmont is remembered today largely for his ideas on spontaneous generation, his 5-year willow tree experiment, and his introduction of the word "gas" (from the Greek word ''chaos'') into the vocabulary of science. His name is also found rendered as Jan-Baptiste van Helmont, Johannes Baptista van Helmont, Johann Baptista von Helmont, Joan Baptista van Helmont, and other minor variants switching between ''von'' and ''van''. Early life and education Jan Baptist van Helmont was the youngest of five children of Maria (van) Stassaert and Christiaen van Helmont, a public prosecutor and Brussels council member, who had married in the Sint-Goedele church in 1567.Van den Bulck, E. (1999Johannes Bapti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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