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Trichloromethane
Chloroform, or trichloromethane (often abbreviated as TCM), is an organochloride with the chemical formula, formula and a common solvent. It is a Volatility (chemistry), volatile, colorless, sweet-smelling, dense liquid produced on a large scale as a precursor to refrigerants and Polytetrafluoroethylene, polytetrafluoroethylene (PTFE). Chloroform was once used as an inhalational anesthetic between the 19th century and the first half of the 20th century. It is miscible with many solvents but it is only very slightly soluble in water (only 8 g/L at 20°C). Structure and name The molecule adopts a tetrahedral molecular geometry with C3v symmetry group, symmetry. The chloroform molecule can be viewed as a methane molecule with three hydrogen atoms replaced with three chlorine atoms, leaving a single hydrogen atom. The name "chloroform" is a portmanteau of ''terchloride'' (tertiary chloride, a trichloride) and ''formyle'', an obsolete name for the methylylidene radical (CH) derived ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrachloromethane
Carbon tetrachloride, also known by many other names (such as carbon tet for short and tetrachloromethane, also IUPAC nomenclature of inorganic chemistry, recognised by the IUPAC), is a chemical compound with the chemical formula CCl4. It is a non-flammable, dense, colourless liquid with a "sweet" chloroform-like odour that can be detected at low levels. It was formerly widely used in fire extinguishers, as a precursor to refrigerants, an anthelmintic and a cleaning agent, but has since been phased out because of environmental and safety concerns. Exposure to high concentrations of carbon tetrachloride can affect the central nervous system and degenerate the liver and kidneys. Prolonged exposure can be fatal. Properties In the carbon tetrachloride molecule, four chlorine atoms are positioned symmetrically as corners in a tetrahedron, tetrahedral configuration joined to a central carbon atom by single covalent bonds. Because of this symmetric geometry, CCl4 is non-polar. methane, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dichloromethane
Dichloromethane (DCM, methylene chloride, or methylene bichloride) is an organochlorine compound with the formula . This colorless, volatile liquid with a chloroform-like, sweet odor is widely used as a solvent. Although it is not miscible with water, it is slightly polar, and miscible with many organic solvents.Rossberg, M. ''et al.'' (2006) "Chlorinated Hydrocarbons" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim. . Occurrence Natural sources of dichloromethane include oceanic sources, macroalgae, wetlands, and volcanoes. However, the majority of dichloromethane in the environment is the result of industrial emissions. Production DCM is produced by treating either chloromethane or methane with chlorine gas at 400–500 °C. At these temperatures, both methane and chloromethane undergo a series of reactions producing progressively more chlorinated products. In this way, an estimated 400,000 tons were produced in the US, Europe, and Japan in 199 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latin
Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area around Rome, Italy. Through the expansion of the Roman Republic, it became the dominant language in the Italian Peninsula and subsequently throughout the Roman Empire. It has greatly influenced many languages, Latin influence in English, including English, having contributed List of Latin words with English derivatives, many words to the English lexicon, particularly after the Christianity in Anglo-Saxon England, Christianization of the Anglo-Saxons and the Norman Conquest. Latin Root (linguistics), roots appear frequently in the technical vocabulary used by fields such as theology, List of Latin and Greek words commonly used in systematic names, the sciences, List of medical roots, suffixes and prefixes, medicine, and List of Latin legal terms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Society Of Chemistry
The Royal Society of Chemistry (RSC) is a learned society and professional association in the United Kingdom with the goal of "advancing the chemistry, chemical sciences". It was formed in 1980 from the amalgamation of the Chemical Society, the Royal Institute of Chemistry, the Faraday Society, and the Society for Analytical Chemistry with a new Royal Charter and the dual role of learned society and professional body. At its inception, the Society had a combined membership of 49,000 in the world. The headquarters of the Society are at Burlington House, Piccadilly, London. It also has offices in Thomas Graham House in Cambridge (named after Thomas Graham (chemist), Thomas Graham, the first president of the Chemical Society) where ''RSC Publishing'' is based. The Society has offices in the United States, on the campuses of The University of Pennsylvania and Drexel University, at the University City Science Center in Philadelphia, Pennsylvania, in both Beijing and Shanghai, People' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dibromochloromethane
Dibromochloromethane is a colorless to yellow, heavy and nonflammable compound with formula . It is a trihalomethane. The substance has a sweet odour. Small quantities of dibromochloromethane are produced in ocean by algae. Applications Dibromochloromethane was formerly used as a flame retardant and as an intermediate in chemicals manufacturing. Today it is used only as a laboratory reagent. Dibromochloromethane is also a disinfection byproduct, formed by the reaction of chlorine with natural organic matter and bromide ions in the raw water supply. As a result, it is commonly found in chlorinated drinking water. Also, it is able to reduce methane production in ruminants by 79 % See also * Asparagopsis taxiformis References External links Dibromochlormethane in greenfacts.org glossaryToxFAQ for bromoform at ATSDR {{halomethanes Bromochloroalkanes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromodifluoromethane
Bromodifluoromethane or Halon 1201 or FC-22B1 is a gaseous trihalomethane or a hydrobromofluorocarbon. Synthesis It can be prepared through the reaction of hydrogen and dibromodifluoromethane at temperature in range 400–600 °C. Critical point data: ''T''c = 138.83 °C (411.98K); pc = 5.2MPa (51.32bar); ''V''c = 0.275dm3·mol−1. Applications Bromodifluoromethane was used as a refrigerant and in fire extinguishers. It is a class I ozone depleting substance with ozone depletion potential ODP = 0.74, and a greenhouse gas with global warming potential over 100 years of 398, which is nonetheless much smaller than other fluorinated gases due to its relatively short atmospheric lifetime of 5.2 years. It was banned by the Montreal Protocol The Montreal Protocol on Substances That Deplete the Ozone Layer is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dibromofluoromethane
Dibromofluoromethane is a mixed halomethane. It is soluble in alcohol, acetone, benzene and chloroform. It is prepared from dibromomethane and antimony(III) fluoride. Applications It can be used to prepare bromofluoromethane by reductive debromination with organotin hydride as tributyltin hydride. Regulations Its ozone depletion potential The ozone depletion potential (ODP) of a chemical compound is the relative amount of degradation to the ozone layer it can cause, with trichlorofluoromethane (R-11 or CFC-11) being fixed at an ODP of 1.0. Chlorodifluoromethane (R-22), for examp ... (ODP) is 1.0 and it is included in list of Class I Ozone-Depleting Substances. References {{Halomethanes Halomethanes Bromofluoroalkanes Ozone-depleting chemical substances ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Formula
A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and ''plus'' (+) and ''minus'' (−) signs. These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a chemical name since it does not contain any words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulae can fully specify the structure of only the simplest of molecules and chemical substances, and are generally more limited in power than chemical names and structural formulae. The simplest types of chemical formulae are called '' empirical formulae'', which use letters and numbers indicating the numerical ''proportions'' of atoms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organochloride
Organochlorine chemistry is concerned with the properties of organochlorine compounds, or organochlorides, organic compounds that contain one or more carbon–chlorine bonds. The chloroalkane class (alkanes with one or more hydrogens substituted by chlorine) includes common examples. The wide structural variety and divergent chemical properties of organochlorides lead to a broad range of names, applications, and properties. Organochlorine compounds have wide use in many applications, though some are of profound environmental concern, with TCDD being one of the most notorious. Organochlorides such as trichloroethylene, tetrachloroethylene, dichloromethane and chloroform are commonly used as solvents and are referred to as "chlorinated solvents". Physical and chemical properties Chlorination modifies the physical properties of hydrocarbons in several ways. These compounds are typically denser than water due to the higher atomic weight of chlorine versus hydrogen. They have hig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dichlorofluoromethane
Dichlorofluoromethane or Freon 21 or R 21 is a halomethane or hydrochlorofluorocarbon with the formula CHCl2F. It is a colorless and odorless gas. It is produced by fluorination of chloroform using a catalyst such as antimony trifluoride: :CHCl3 + HF → CHCl2F + HCl Uses Dichlorofluoromethane was used as a propellant and refrigerant. Due to its role in ozone depletion, dichlorofluoromethane has been largely phased out. It has ozone depletion potential 0.04. Production and consumption has been since 2004 reduced to 15% of level from 1989 and it is to be phased out in 2015 according to Montreal Protocol. Pyrolysis of a mixture of dichlorofluoromethane and chlorofluoromethane gives hexafluorobenzene: :3 CHCl2F + 3 CH2ClF → C6F6 + 9 HCl Additional physical data Its critical point is at 178.5 °C (451.7K) and 5.17MPa (51.7bar). At temperatures from 5K to 105K, it has one phase in the space group Pbca. Safety Its toxicity is comparable to that of chloroform Chloroform, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solvent
A solvent (from the Latin language, Latin ''wikt:solvo#Latin, solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a Solution (chemistry), solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for Chemical polarity#Polarity of molecules, polar molecules, and the most common solvent used by living things; all the ions and proteins in a Cell (biology), cell are dissolved in water within the cell. Major uses of solvents are in paints, paint removers, inks, and dry cleaning. Specific uses for Organic compound, organic solvents are in dry cleaning (e.g. tetrachloroethylene); as paint thinners (toluene, turpentine); as nail polish removers and solvents of glue (acetone, methyl acetate, ethyl acetate); in spot removers (hexane, petrol ether); in detergents (D-limonene, citrus terpenes); and in perfumes (ethanol). Solvents find various applications in chemical, pharmaceutical, oil, and gas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
