Swan's riffing is as heavy and eccentric as ever, building up to boiling points and heavy catharses like never before.
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Lady Gaga Back when she was still known as Stefani Germanotta, the superstar's temper was tested on MTV prank show Boiling Points.
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This feature, I might add, is especially handy for frothing various sorts of milk, which all have their own consistencies and boiling points.
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This was done using a gas chromatograph, in which compounds are separated out from a sample based upon their boiling points and chemical properties.
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All except helium were products of the newly developed technology of cryogenics, which he used to liquefy air and then separate it into its components, according to their boiling points.
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In order to convert each gas into liquid form, the air expansion engine lowers the temperature of the air to reach negative boiling points, separating oxygen and nitrogen from air.
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It has a suitable atmospheric pressure and surface temperatures between liquid water's freezing and boiling points, 0 to 100 degrees Celsius (or 32 to 212 in those quaint "Fahrenheit" degrees).
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Distillation helps separate the water, ethanol and methanol out based on their boiling points—ethanol has a boiling point of 173.1 degrees Fahrenheit, and methanol has a boiling point of 148.5 degrees Fahrenheit.
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In either case, you'd expect that nowadays you'd see relatively few volatile elements or compounds — such as sulfur and ammonia — which have low boiling points and would presumably have been vaporized during the process.
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Then, the researchers ran a model to see if vaporization of some specific elements with lower boiling points called volatiles could have accounted for the Earth's present-day composition—and their model matched the data quite well.
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"The unique part about temperature when it comes to cannabis consumption is that every single one of those active compounds — all your cannabinoids ... all of your terpenes ... add to your holistic high and they all have different boiling points," O'Brien explained.
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Distillation is the most common way to separate chemicals with different boiling points. The greater the difference in boiling points, the easier it is to do. However, when boiling points are too similar, this isn't feasible. Adsorption separation might be possible.
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Their boiling points are high and their solubility in water is low.
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Volatility itself has no defined numerical value, but it is often described using vapor pressures or boiling points (for liquids). High vapor pressures indicate a high volatility, while high boiling points indicate low volatility. Vapor pressures and boiling points are often presented in tables and charts that can be used to compare chemicals of interest. Volatility data is typically found through experimentation over a range of temperatures and pressures.
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This reactor is often utilized in order to handle feeds with extremely high boiling points.
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If the difference in boiling points is greater than 25 °C, a simple distillation is typically used.
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This method is effective when the volatile compounds have lower boiling points than water or have limited solubility in water.
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One of the first historical QSAR applications was to predict boiling points. It is well known for instance that within a particular family of chemical compounds, especially of organic chemistry, that there are strong correlations between structure and observed properties. A simple example is the relationship between the number of carbons in alkanes and their boiling points. There is a clear trend in the increase of boiling point with an increase in the number carbons, and this serves as a means for predicting the boiling points of higher alkanes.
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The formula used for the prediction of the normal boiling point shows another problem. Joback assumed a constant contribution of added groups in homologous series like the alkanes. This doesn't describe the real behavior of the normal boiling points correctly.Stein S. E., Brown R. L., "Estimation of Normal Boiling Points from Group Contributions", J. Chem. Inf. Comput. Sci.
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The melting points of the alkanes follow a similar trend to boiling points for the same reason as outlined above. That is, (all other things being equal) the larger the molecule the higher the melting point. There is one significant difference between boiling points and melting points. Solids have more rigid and fixed structure than liquids.
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Fluoride volatility is the tendency of highly fluorinated molecules to vaporize at comparatively low temperatures. Heptafluorides, hexafluorides and pentafluorides have much lower boiling points than the lower-valence fluorides. Most difluorides and trifluorides have high boiling points, while most tetrafluorides and monofluorides fall in between. The term "fluoride volatility" is jargon used particularly in the context of separation of radionuclides.
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There are other advantages, such as the ability to distill liquids with high boiling points and avoiding decomposition of substances that are heat sensitive.
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Such molten salts are "chemically stable" when maintained well below their boiling points. Fluoride salts dissolve poorly in water, and do not form burnable hydrogen.
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They are colourless , tasteless and odorless gases. They exhibit low melting and boiling points. They have high positive electron gain enthalpy and high ionization enthalpy.
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A few key properties, such as its melting and boiling points and its first ionization energy, are nevertheless expected to follow the periodic trends of the halogens.
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The major side- products are ethyl acetate, formic acid, and formaldehyde, all of which have lower boiling points than acetic acid and are readily separated by distillation.
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Spinning band distillation is a technique used to separate liquid mixtures which are similar in boiling points. When liquids with similar boiling points are distilled, the vapors are mixtures, and not pure compounds. Fractionating columns help separate the mixture by allowing the mixed vapors to cool, condense, and vaporize again in accordance with Raoult's law. With each condensation-vaporization cycles, the vapors are enriched in a certain component.
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Thiols show little association by hydrogen bonding, both with water molecules and among themselves. Hence, they have lower boiling points and are less soluble in water and other polar solvents than alcohols of similar molecular weight. For this reason also, thiols and their corresponding sulfide functional group isomers have similar solubility characteristics and boiling points, whereas the same is not true of alcohols and their corresponding isomeric ethers.
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The boiling points of the pentane isomers range from about 9 to 36 °C. As is the case for other alkanes, the more thickly branched isomers tend to have lower boiling points. The same tends to be true for the melting points of alkane isomers, and that of isopentane is 30 °C lower than that of n-pentane. However, the melting point of neopentane, the most heavily branched of the three, is 100 °C higher than that of isopentane.
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Comparison of the boiling points of hydrogen halides and hydrogen chalcogenides; here it can be seen that hydrogen fluoride breaks trends alongside water. The hydrogen halides are colourless gases at standard conditions for temperature and pressure (STP) except for hydrogen fluoride, which boils at 19 °C. Alone of the hydrogen halides, hydrogen fluoride exhibits hydrogen bonding between molecules, and therefore has the highest melting and boiling points of the HX series. From HCl to HI the boiling point rises.
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The separation of perchloromethyl mercaptan from S2Cl2 by distillation is challenging since their boiling points are very close. Another byproduct that forms is hexachloroethane. Innovations in the basic Rathke method have been reported.
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The CFCs have still higher boiling points because the chloride is even more polarizable than fluoride. Because of their polarity, the CFCs are useful solvents, and their boiling points make them suitable as refrigerants. The CFCs are far less flammable than methane, in part because they contain fewer C-H bonds and in part because, in the case of the chlorides and bromides, the released halides quench the free radicals that sustain flames. The densities of CFCs are higher than their corresponding alkanes.
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A Kugelrohr (German for "ball tube") is a short-path vacuum distillation apparatus typically used to distill relatively small amounts of compounds with high boiling points (usually greater than 300 °C) under greatly reduced pressure.
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As implied by the name, all transition metals are metals and thus conductors of electricity. In general, transition metals possess a high density and high melting points and boiling points. These properties are due to metallic bonding by delocalized d electrons, leading to cohesion which increases with the number of shared electrons. However the group 12 metals have much lower melting and boiling points since their full d sub-shells prevent d–d bonding, which again tends to differentiate them from the accepted transition metals.
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For samples with high boiling points, short-path distillation apparatus is commonly employed.Introduction to Organic Laboratory Techniques: A Small Scale Approach By Donald L. Pavia, Gary M. Lampman, George S. Kriz, Randall G. Engel. Chapter 16.
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The boiling points of selenols tend to be slightly greater than for thiols. This can be attributed to the increased importance of stronger van der Waals bonding for larger atoms. Volatile selenols have highly offensive odors.
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In 1978, the United States banned the use of CFCs like Freon 11 and 12 in aerosol cans. The manufacturers then changed the formulation to use permitted propellants. Aerosol propellants are liquids with very low boiling points.
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The elements undergo fractionation during particle formation, due to their different volatility. Refractory elements (Sr, Y, Zr, Nb, Ba, La, Ce, Pr, Nd, Pm) form oxides with high boiling points; these precipitate the fastest and at the time of particle solidification, at temperature of 1400 °C, are considered to be fully condensed. Volatile elements (Kr, Xe, I, Br) are not condensed at that temperature. Intermediate elements have their (or their oxides) boiling points close to the solidification temperature of the particles (Rb, Cs, Mo, Ru, Rh, Tc, Sb, Te).
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The "lightest" products with the lowest boiling points exit from the top of the columns and the "heaviest" products with the highest boiling points exit from the bottom. Industrial fractionating columns use external reflux to achieve better separation of products. Reflux refers to the portion of the condensed overhead liquid product that returns to the upper part of the fractionating column as shown in Figure 3. Inside the column, the downflowing reflux liquid provides cooling and condensation of upflowing vapors thereby increasing the efficacy of the distillation tower.
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In the preceding section, boiling points of pure compounds were covered. Vapor pressures and boiling points of substances can be affected by the presence of dissolved impurities (solutes) or other miscible compounds, the degree of effect depending on the concentration of the impurities or other compounds. The presence of non- volatile impurities such as salts or compounds of a volatility far lower than the main component compound decreases its mole fraction and the solution's volatility, and thus raises the normal boiling point in proportion to the concentration of the solutes. This effect is called boiling point elevation.
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Several kinds of descriptive categorizations can be applied broadly to the elements, including consideration of their general physical and chemical properties, their states of matter under familiar conditions, their melting and boiling points, their densities, their crystal structures as solids, and their origins.
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The reaction route does not appear to be dependent on the type of solvents utilized. However, the nature of the solvent can influence the activity of the catalyst. Those solvents with low boiling points appear to lead to an increase in catalytic activity.
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The heaviest materials in crude petroleum are not distilled, as their boiling points are too high to be conveniently recovered. As a result, bunker oil is usually very dark in color, more dense, and a significantly more serious contaminant than less-dense oils.
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The Me2SiCl2 is purified by fractional distillation. Although the boiling points of the various chloro methyl silanes are similar (Me2SiCl2:70 C, MeSiCl3: 66 C, Me3SiCl: 57 C, MeHSiCl2: 41 C, Me2HSiCl: 35 C), the distillation utilizes columns with high separating capacities, connected in series.
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This phenomenon is used in processes such as steaming. Since liquids often have different boiling points, mixtures or solutions of liquids or gases can typically be separated by distillation, using heat, cold, vacuum, pressure, or other means. Distillation can be found in everything from the production of alcoholic beverages, to oil refineries, to the cryogenic distillation of gases such as argon, oxygen, nitrogen, neon, or xenon by liquefaction (cooling them below their individual boiling points).Unit Operations in Food Processing by R. L. Earle -- Pergamon Press 1983 Page 56--62, 138--141 Liquid is the primary component of hydraulic systems, which take advantage of Pascal's law to provide fluid power.
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In physics, cryogenics is the production and behaviour of materials at very low temperatures. It is not well defined at what point on the temperature scale refrigeration ends and cryogenics begins, but scientists assume a gas to be cryogenic if it can be liquefied at or below . The U.S. National Institute of Standards and Technology considers the field of cryogenics as that involving temperatures below . This is a logical dividing line, since the normal boiling points of the so-called permanent gases (such as helium, hydrogen, neon, nitrogen, oxygen, and normal air) lie below −180 °C while the Freon refrigerants, hydrocarbons, and other common refrigerants have boiling points above −180 °C.
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The boiling points of components in an azeotrope overlap to form a band. By exposing an azeotrope to a vacuum or positive pressure, it's possible to bias the boiling point of one component away from the other by exploiting the differing vapor pressure curves of each; the curves may overlap at the azeotropic point, but are unlikely to be remain identical further along the pressure axis either side of the azeotropic point. When the bias is great enough, the two boiling points no longer overlap and so the azeotropic band disappears. This method can remove the need to add other chemicals to a distillation, but it has two potential drawbacks.
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Boiling points vary with the proportion of isopropyl alcohol from ; likewise, freezing points vary from . Surgical spirit BP boils at . Naturally colorless, products may contain color additives. They may also contain medically-inactive additives for fragrance, such as wintergreen oil (methyl salicylate), or for other purposes.
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The chemistry of hafnium and zirconium is so similar that the two cannot be separated on the basis of differing chemical reactions. The melting points and boiling points of the compounds and the solubility in solvents are the major differences in the chemistry of these twin elements.
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The difference between the two categories is more of degree than kind. The subject metals are light, reactive, and mostly of low mechanical strength, melting and boiling points. The group 1 members are easily cut with a knife. Only Be and Mg have any structural uses.
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The element with the lowest boiling point is helium. Both the boiling points of rhenium and tungsten exceed 5000 K at standard pressure; because it is difficult to measure extreme temperatures precisely without bias, both have been cited in the literature as having the higher boiling point.
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If Kn > 1, the system is in free molecular flow. In free molecular flow, the pressure of the remaining gas can be considered as effectively zero. Thus, boiling points do not depend on the residual pressure. The flow can be considered to be individual particles moving in straight lines.
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Butanol, with a four-carbon chain, is moderately soluble. Because of hydrogen bonding, alcohols tend to have higher boiling points than comparable hydrocarbons and ethers. The boiling point of the alcohol ethanol is 78.29 °C, compared to 69 °C for the hydrocarbon hexane, and 34.6 °C for diethyl ether.
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Since molecular solids are held together by relatively weak forces they tend to have low melting and boiling points, low mechanical strength, low electrical conductivity, and poor thermal conductivity. Also, depending on the structure of the molecule the intermolecular forces may have directionality leading to anisotropy of certain properties.
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A rare type of complex binary azeotrope is one where the boiling point and condensation point curves touch at two points in the phase diagram. Such a system is called a double azeotrope, and will have two azeotropic compositions and boiling points. An example is water and N-methylethylenediamine.
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Compounds with a boiling point lower than 150 °C can typically be distilled at ambient pressure. A fractionating column allow separation of compounds with similar boiling points. A variety of apparatus is commercially available. In addition to the distillation apparatus, a vacuum pump, heat source, and a vacuum gauge are required.
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The boiling points of the carbon group tend to get lower with the heavier elements. Carbon, the lightest carbon group element, sublimates at 3825 °C. Silicon's boiling point is 3265 °C, germanium's is 2833 °C, tin's is 2602 °C, and lead's is 1749 °C. Flerovium is predicted boil in -60°C.
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Hexane () is a straight-chain alkane with six carbon atoms and has the molecular formula C6H14. Hexane is a significant constituent of gasoline. It is a colorless liquid, odorless when pure, and with boiling points approximately . It is widely used as a cheap, relatively safe, largely unreactive, and easily evaporated non-polar solvent.
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Carl L. Yaws (2008) Thermophysical Properties of Chemicals and Hydrocarbons. 800 pages. Alexandru T. Balaban, Subhash C. Basak, Timothy Colburn, and Gregory D. Grunwald (1994): "Correlation between structure and normal boiling points of haloalkanes C1-C4 using neural networks". Journal of Chemical Information and Computer Science, volume 34, issue 5, pages 1118–1121.
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The resulting ternary azeotrope is neither positive nor negative. Its boiling point falls between the boiling points of acetone and chloroform, so it is neither a maximum nor a minimum boiling point. This type of system is called a saddle azeotrope. Only systems of three or more constituents can form saddle azeotropes.
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Phenylsilane, also known as silylbenzene, a colorless liquid, is one of the simplest organosilanes with the formula C6H5SiH3. It is structurally related to toluene, with a silyl group replacing the methyl group. Both of these compounds have similar densities and boiling points due to these similarities. Phenylsilane is soluble in organic solvents.
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A process called fractional distillation separates crude oil into various segments. Fractions at the top have a lower boiling points than fractions at the bottom. The bottom fractions are heavy, and are thus "cracked" into lighter and more useful products. Directly from the well, raw or unprocessed ("crude") oil is not useful.
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3,9-Divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane is without impurity a white crystalline powder. However, DVTOSU is often sold as a liquid, due to its low crystallization tendency. The highly variable data on yields and boiling points during the first fractionated distillation indicate by-products, e.g. by rearrangement of the double bonds or nucleophilic addition.
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Like asymmetrically disubstituted hydrazines, they are liquids, but their boiling points are typically higher. In particular, the aliphatic compounds are basic and reducing agents and are soluble in water. Aromatic symmetric disubstituted hydrazines are not soluble in water. Symmetrically disubstituted hydrazines are prepared by reducing nitro compounds under basic conditions or by reducing the azines.
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Moderate to high density metals, with high melting and boiling points; many have high hardness, mechanical strength and corrosion resistance. Those from Rf onwards are synthetic. Chemically, they show variable valency and a strong tendency to form coordination and brightly colored compounds. The oxides are basic, amphoteric or acidic, depending on the oxidation state.
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Its melting and boiling points are respectively 770 °C and 921 °C. It undergoes a phase transition at 405 °C, with a low-temperature α phase and high-temperature β phase. Nevertheless, the β phase usually persists below the transition temperature. Both phases crystallise in the tetragonal crystal system and the structural differences are small.
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Steam Traps operate on the difference of properties between steam and condensate. Condensate will collect at the lowest point since steam is about 1600 times greater in volume than its liquid phase. Steam properties also change with pressure, at different pressures there are different boiling points. Steam traps can be split into 3 main categories; Mechanical, Thermodynamic, and Thermostatic.
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Rebekka Johnson is an American actress, comedian and writer, from Staten Island, New York. Johnson is best known for playing Dawn Rivecca on Netflix's wrestling comedy GLOW. She was featured on MTV's prank show Boiling Points. Johnson has been performing with her musical comedy group The Apple Sisters along with Kimmy Gatewood and Sarah Lowe since 2007.
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The boiling point of 89.7 °C is 0.3 °C higher than the value 89.4 °C predicted by Wiener's formula, based on the structure of the molecule and the boiling point of n-heptane.Harry Wiener (1947): "Structural Determination of Paraffin Boiling Points". Journal of the American Chemical Society, volume 69, issue 1, pages 17–20. Pentane, 2,3-dimethyl-.
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Cycloalkanes have similar properties to alkanes but have higher boiling points. The aromatic hydrocarbons are unsaturated hydrocarbons which have one or more planar six-carbon rings called benzene rings, to which hydrogen atoms are attached with the formula CnH2n-6. They tend to burn with a sooty flame, and many have a sweet aroma. Some are carcinogenic.
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Although the specifics vary depending on the compound, in simple disubstituted arenes, the three isomers tend to have rather similar boiling points. However, the para isomer usually has the highest melting point, and the lowest solubility in a given solvent, of the three isomers.Morrison and Boyd, Organic Chemistry, Allyn and Bacon Inc, Boston, 1959. Ch.9, p. 250.
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A polar molecule with two or more polar bonds must have a geometry which is asymmetric in at least one direction, so that the bond dipoles do not cancel each other. Polar molecules interact through dipole–dipole intermolecular forces and hydrogen bonds. Polarity underlies a number of physical properties including surface tension, solubility, and melting and boiling points.
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The vapour contacts a cool surface where it condenses as a liquid. Because the solutes are not normally vaporised, they remain in the boiling solution. Even distillation does not completely purify water, because of contaminants with similar boiling points and droplets of unvapourised liquid carried with the steam. However, 99.9% pure water can be obtained by distillation.
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As the difference in boiling points between the two compounds is only 9 °C at ambient pressure this necessitates the use of a series of distillation columns. This is energy intensive and is further complicated by the tendency of styrene to undergo thermally induced polymerisation into polystyrene, requiring the continuous addition of polymerization inhibitor to the system.
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Newton's system was calibrated between the freezing point of water (0 degrees) and human body temperature (12 degrees); it was a coarser scale, but unlike Rømer's it was not intended for everyday use, as Newton's interest was in determining the boiling points of metals, which are not readily accessible with Rømer's system based on liquid thermometers.
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Its melting and boiling points are also significantly lower than those of thulium and lutetium. This is due to the closed-shell electron configuration of ytterbium ([Xe] 4f14 6s2), which causes only the two 6s electrons to be available for metallic bonding (in contrast to the other lanthanides where three electrons are available) and increases ytterbium's metallic radius.
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Various authors have credited the invention of the thermometer to Cornelis Drebbel, Robert Fludd, Galileo Galilei or Santorio Santorio. The thermometer was not a single invention, however, but a development. However, each inventor and each thermometer was unique – there was no standard scale. In 1665 Christiaan Huygens suggested using the melting and boiling points of water as standards.
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Styrene is separated from ethyl benzene in a very tall continuously packed distillation tower. This separation is difficult because of the close boiling points of ethylbenzene and styrene; 136 degrees C and 145 degrees C respectively. This column is the tallest distillation column in Australia. The ethylbenzene coming out of the column is recycled to the Alkylation plant.
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However, careful application also allows removal of a solvent from a sample containing a liquid compound if there is minimal co-evaporation (azeotropic behavior), and a sufficient difference in boiling points at the chosen temperature and reduced pressure. Solvents with higher boiling points such as water (100 °C at standard atmospheric pressure, 760 torr or 1 bar), dimethylformamide (DMF, 153 °C at the same), or dimethyl sulfoxide (DMSO, 189 °C at the same), can also be evaporated if the unit's vacuum system is capable of sufficiently low pressure. (For instance, both DMF and DMSO will boil below 50 °C if the vacuum is reduced from 760 torr to 5 torr [from 1 bar to 6.6 mbar]) However, more recent developments are often applied in these cases (e.g., evaporation while centrifuging or vortexing at high speeds).
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A fraction in chemistry is a quantity collected from a batch of a substance in a fractionating separation process. In such a process, a mixture is separated into fractions, which have compositions that vary according to a gradient. A fraction can be defined as a group of chemicals that have similar boiling points. A common fractionating process is fractional distillation.
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The metals of the s-block (from the second period onwards) are mostly soft and have generally low melting and boiling points. Most impart colour to a flame. Chemically, all s-elements except helium are highly reactive. Metals of the s-block are highly electropositive and often form essentially ionic compounds with nonmetals, especially with the highly electronegative halogen nonmetals.
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This means that even room temperature ionic liquids have low vapour pressures, and require substantially higher temperatures to boil. Boiling points exhibit similar trends to melting points in terms of the size of ions and strength of other interactions. When vapourized, the ions are still not freed of one another. For example, in the vapour phase sodium chloride exists as diatomic "molecules".
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A Perkin triangle is a specialized apparatus for the distillation of air- sensitive materials. It is named after William Henry Perkin Jr., whose design was approximately triangular in shape. The diagram shows a more modern version, in which the glass taps have been replaced with more air-tight Teflon taps. Some compounds have high boiling points and are sensitive to air.
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The properties of water have historically been used to define various temperature scales. Notably, the Kelvin, Celsius, Rankine, and Fahrenheit scales were, or currently are, defined by the freezing and boiling points of water. The less common scales of Delisle, Newton, Réaumur and Rømer were defined similarly. The triple point of water is a more commonly used standard point today.
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N-Methylation of aniline with methanol at elevated temperatures over acid catalysts gives N-methylaniline and dimethylaniline: :C6H5NH2 \+ 2 CH3OH → C6H5N(CH3)2 \+ 2H2O N-Methylaniline and dimethylaniline are colorless liquids with boiling points of 193–195 °C and 192 °C, respectively. These derivatives are of importance in the color industry. Aniline combines directly with alkyl iodides to form secondary and tertiary amines.
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In addition, tests with animals have shown fish and insects able to distinguish isotopes by smell.Flies sniff out heavy hydrogen Nature 14 February 2011. Deuteration changes the heats of adsorption and the boiling and freezing points of molecules (boiling points: 100.0 °C for H2O vs. 101.42 °C for D2O; melting points: 0.0 °C for H2O, 3.82 °C for D2O), pKa (i.e.
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Becker is a regular player at the Upright Citizens Brigade improv theatre. She has also performed for Hopscotch: A New York Sex Comedy, Caroline's on Broadway, and other comedy clubs. She starred on Boiling Points, the MTV prank television show. She was a VJ on the music video TV channel Fuse, where she hosted F-List and some other shows.
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A Perkin triangle is an alternative apparatus often used in these situations because it allows isolation of the receiver from the rest of the system, but does require removing and reattaching a single receiver for each fraction. Vacuum distillation systems operate at reduced pressure, thereby lowering the boiling points of the materials. Anti-bumping granules, however, become ineffective at reduced pressures.
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However, there are disadvantages to cryogenic loading. With the low temperatures indicative of cryogenic loading, the sample is subjected to temperatures that could irreversibly change it. Also, the boiling liquid could displace the sample or trap an air bubble in the chamber. It is not possible to load gas mixtures using the cryogenic method due to the different boiling points of most gases.
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Vaporization is rapid at temperatures above the boiling points. The calorific (heat) values of the two are almost equal. Both are thus mixed to attain the vapor pressure that is required by the end user and depending on the ambient conditions. If the ambient temperature is very low, propane is preferred to achieve higher vapor pressure at the given temperature.
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Wiener showed that the Wiener index number is closely correlated with the boiling points of alkane molecules. Later work on quantitative structure–activity relationships showed that it is also correlated with other quantities including the parameters of its critical point,. the density, surface tension, and viscosity of its liquid phase,. and the van der Waals surface area of the molecule..
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The patent specifically involved the intermediacy of TiI4 and ZrI4, which were volatilized (leaving impurities as solid). At atmospheric pressure TiI4 melts at 150 °C and boils at 377 °C, while ZrI4 melts at 499 °C and boils at 600 °C. The boiling points are lower at reduced pressure. The gaseous metal tetraiodide is decomposed on a white hot tungsten filament (1400 °C).
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Before World War II, engine coolant was usually plain water. Antifreeze was used solely to control freezing, and this was often only done in cold weather. Development in high-performance aircraft engines required improved coolants with higher boiling points, leading to the adoption of glycol or water-glycol mixtures. These led to the adoption of glycols for their antifreeze properties.
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Consider temperature, for example. In the familiar everyday instances, temperature is measured using instruments calibrated in either the Fahrenheit or Celsius scales. What are really being measured with such instruments are the magnitudes of temperature differences. For example, Anders Celsius defined the unit of the Celsius scale to be 1/100th of the difference in temperature between the freezing and boiling points of water at sea level.
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Lithium metal is soft enough to be cut with a knife. When cut, it possesses a silvery- white color that quickly changes to gray as it oxidizes to lithium oxide. While it has one of the lowest melting points among all metals (), it has the highest melting and boiling points of the alkali metals. Lithium has a very low density (0.534 g/cm3), comparable with pine wood.
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Beginning to sober, Alan wonders aloud whether Farrah will return. The next morning Mat and Alan begin to reach their respective boiling points. Unable to open a locked bathroom door, the brothers begin stabbing at the door with a kitchen knife before turning their aggression on each other. Alan various problems overflow and he briefly sees a visage of his infirmed father before confronting Mat.
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The Wurtz reaction is seldom used because of side reactions.March Advanced Organic Chemistry 7th edition p. 512 It has limited use to the synthesis of symmetric alkanes. If two dissimilar alkyl halides are taken as reactants, then the product is a mixture of alkanes that is often difficult to separate by fractional distillation as the differences between the boiling points of the products are typically very low.
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One is to use infrared lamps; this is called infrared reflow. Another is to use a hot gas convection. Another technology which is becoming popular again is special fluorocarbon liquids with high boiling points which use a method called vapor phase reflow. Due to environmental concerns, this method was falling out of favor until lead-free legislation was introduced which requires tighter controls on soldering.
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Fractional distillation is the separation of a mixture into its component parts, or fractions. Chemical compounds are separated by heating them to a temperature at which one or more fractions of the mixture will vaporize. It uses distillation to fractionate. Generally the component parts have boiling points that differ by less than 25 °C (45 °F) from each other under a pressure of one atmosphere.
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Pelc and Fujita, 2002 Systems may be either closed-cycle or open- cycle. Closed-cycle OTEC uses working fluids that are typically thought of as refrigerants such as ammonia or R-134a. These fluids have low boiling points, and are therefore suitable for powering the system’s generator to generate electricity. The most commonly used heat cycle for OTEC to date is the Rankine cycle, using a low-pressure turbine.
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Freezing and boiling points are colligative properties of a solution, which depend on the concentration of dissolved substances. Hence salts lower the melting points of aqueous solutions. Salts are frequently used for de-icing, but salt solutions are not used for cooling systems because they induce corrosion of metals. Low molecular weight organic compounds tend to have melting points lower than water, which recommends them as antifreeze agents.
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Figure 1: At atmospheric pressure, dimethyl sulfoxide boils at 189 °C. In the vacuum apparatus here, it distills off into the connected receiver flask on the left at only 70 °C. Vacuum distillation is distillation performed under reduced pressure, which allows the purification of compounds not readily distilled at ambient pressures or simply to save time or energy. This technique separates compounds based on differences in boiling points.
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Haloalkanes generally resemble the parent alkanes in being colorless, relatively odorless, and hydrophobic. The melting and boiling points of chloro-, bromo-, and iodoalkanes are higher than the analogous alkanes, scaling with the atomic weight and number of halides. This is due to the increased strength of the intermolecular forces—from London dispersion to dipole-dipole interaction because of the increased polarizability. Thus tetraiodomethane () is a solid whereas tetrachloromethane () is a liquid.
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The melting points of the carbon group elements have roughly the same trend as their boiling points. Silicon melts at 1414 °C, germanium melts at 939 °C, tin melts at 232 °C, and lead melts at 328 °C. Carbon's crystal structure is hexagonal; at high pressures and temperatures it forms diamond (see below). Silicon and germanium have diamond cubic crystal structures, as does tin at low temperatures (below 13.2 °C).
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The boiling point of an element at a given pressure is a characteristic attribute of the element. This is also true for many simple compounds including water and simple alcohols. Once boiling has started and provided that boiling remains stable and the pressure is constant, the temperature of the boiling liquid remains constant. This attribute led to the adoption of boiling points as the definition of 100°C.
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For example, consider three compounds of similar chemical composition: sodium n-butoxide (C4H9ONa), diethyl ether (C4H10O), and n-butanol (C4H9OH). Figure 8. Boiling points of 4-carbon compounds The predominant non-covalent interactions associated with each species in solution are listed in the above figure. As previously discussed, ionic interactions require considerably more energy to break than hydrogen bonds, which in turn are require more energy than dipole–dipole interactions.
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The trends observed in their boiling points (figure 8) shows exactly the correlation expected, where sodium n-butoxide requires significantly more heat energy (higher temperature) to boil than n-butanol, which boils at a much higher temperature than diethyl ether. The heat energy required for a compound to change from liquid to gas is associated with the energy required to break the intermolecular forces each molecule experiences in its liquid state.
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Zinc is a fair conductor of electricity. For a metal, zinc has relatively low melting (419.5 °C) and boiling points (907 °C). The melting point is the lowest of all the d-block metals aside from mercury and cadmium; for this, among other reasons, zinc, cadmium, and mercury are often not considered to be transition metals like the rest of the d-block metals. Many alloys contain zinc, including brass.
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However, each inventor and each thermometer was unique — there was no standard scale. In 1665, Christiaan Huygens (1629–1695) suggested using the melting and boiling points of water as standards and, in 1694, Carlo Renaldini (1615–1698) proposed using them as fixed points on a universal scale. In 1701, Isaac Newton (1642–1726/27) proposed a scale of 12 degrees between the melting point of ice and body temperature.
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On June 3, 2011, "Boiling Points" was confirmed by Dondria to be an upcoming single on her Tumblr Blog. The original song featuring Jermaine Dupri first appeared on her "Dondria Duets 2", Mixtape. It is unclear if the record will be released as a mixtape single, or the first offering from a brand new studio album. Currently, Dondria is in the studio recording songs for her upcoming second album.
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Ionic compounds can also be produced from their constituent ions by evaporation of their solvent, precipitation, freezing, a solid-state reaction, or the electron transfer reaction of reactive metals with reactive non-metals, such as halogen gases. Ionic compounds typically have high melting and boiling points, and are hard and brittle. As solids they are almost always electrically insulating, but when melted or dissolved they become highly conductive, because the ions are mobilized.
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The temperatures at those two points correspond to the boiling points of each of the two pure components. For certain pairs of substances, the two curves also coincide at some point strictly between and . When they meet, they meet tangently; the dew-point temperature always lies above the boiling-point temperature for a given composition when they are not equal. The meeting point is called an azeotrope for that particular pair of substances.
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Cornell (1907) pp. 164–5.One noticeable exception to this physical property connection is conductivity which varies depending on the state of matter (ionic compounds in water) as described by Michael Faraday in 1833 when he noted that ice does not conduct a current. See page 45 of John Tyndall's Faraday as a Discoverer (1868). A comparison of boiling points for compounds formed by ionic and covalent bonds leads us to this conclusion.
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Melting and boiling points, typically expressed in degrees Celsius at a pressure of one atmosphere, are commonly used in characterizing the various elements. While known for most elements, either or both of these measurements is still undetermined for some of the radioactive elements available in only tiny quantities. Since helium remains a liquid even at absolute zero at atmospheric pressure, it has only a boiling point, and not a melting point, in conventional presentations.
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Missy O'Reilly is an actress/comedian best known as a cast member on MTV's hidden camera show Boiling Points. She has also appeared as various characters on Late Night with Conan O'Brien and Upright Citizens Brigade as well appearing in the film Martin & Orloff and New York City Serenade. She is currently a series regular on CMT's Prankville. She is a co-owner of a New York City karaoke lounge called "Planet Rose".
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Different boiling points allow the hydrocarbons to be separated by distillation. Since the lighter liquid products are in great demand for use in internal combustion engines, a modern refinery will convert heavy hydrocarbons and lighter gaseous elements into these higher value products. The oil refinery in Haifa, Israel is capable of processing about 9 million tons (66 million barrels) of crude oil a year. Its two cooling towers are landmarks of the city's skyline.
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The alkali metals are more similar to each other than the elements in any other group are to each other. For instance, when moving down the table, all known alkali metals show increasing atomic radius, decreasing electronegativity, increasing reactivity, and decreasing melting and boiling points as well as heats of fusion and vaporisation. In general, their densities increase when moving down the table, with the exception that potassium is less dense than sodium.
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Many of the elements that form volatile high-valence fluorides will also form volatile high-valence chlorides. Chlorination and distillation is another possible method for separation. The sequence of separation may differ usefully from the sequence for fluorides; for example, zirconium tetrachloride and tin tetrachloride have relatively low boiling points of 331 °C and 114.1 °C. Chlorination has even been proposed as a method for removing zirconium fuel cladding, instead of mechanical decladding.
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Rhenium is a silvery-white metal with one of the highest melting points of all elements, exceeded by only tungsten and carbon. It also has one of the highest boiling points of all elements, and the highest among stable elements. It is also one of the densest, exceeded only by platinum, iridium and osmium. Rhenium has a hexagonal close-packed crystal structure, with lattice parameters a = 276.1 pm and c = 445.6 pm.
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The melting and boiling points of water are no longer part of the definition of the Celsius scale. In 1948, the definition was changed to use the triple point of water. In 2005 the definition was further refined to use water with precisely defined isotopic composition (VSMOW) for the triple point. In 2019, the definition was changed to use the Boltzmann constant, completely decoupling the definition of the kelvin from the properties of water.
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The boiling point corresponds to the temperature at which the vapor pressure of the liquid equals the surrounding environmental pressure. Thus, the boiling point is dependent on the pressure. Boiling points may be published with respect to the NIST, USA standard pressure of 101.325 kPa (or 1 atm), or the IUPAC standard pressure of 100.000 kPa. At higher elevations, where the atmospheric pressure is much lower, the boiling point is also lower.
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This is a severe problem because aromatic and aliphatic components differ strongly. The data base Joback and Reid used for obtaining the group parameters was rather small and covered only a limited number of different molecules. The best coverage has been achieved for normal boiling points (438 components), and the worst for heats of fusion (155 components). Current developments that can use data banks, like the Dortmund Data Bank or the DIPPR data base, have a much broader coverage.
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A second-order analysis of each phase will typically involve a selection among available analytical methods to further separate these components. Analytical methods used on liquid phases might include distillation or one of a variety of chromatographic separation methods. Distillation separates the components of a liquid mixture according to differences in their boiling points. Chomatography separates components of a liquid or gaseous mixture according to differences in retention time as the mixture interacts with a stationary phase.
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Methane is the predominant component of natural gas. The C6 through C10 alkanes, alkenes and isomeric cycloalkanes are the top components of gasoline, naphtha, jet fuel and specialized industrial solvent mixtures. With the progressive addition of carbon units, the simple non-ring structured hydrocarbons have higher viscosities, lubricating indices, boiling points, solidification temperatures, and deeper color. At the opposite extreme from methane lie the heavy tars that remain as the lowest fraction in a crude oil refining retort.
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The process began with a tokamak, a doughnut-shaped magnetic “bottle”, containing plasma and unwanted material. This combination would result in a pool of electrons and nuclei which in turn would cause the tokamak to overflow and transfer the plasma into an outlet. This plasma then passes through a series of metal plates, differing in particular temperatures, all arranged in descending order. The atoms of elements pass over the plates with boiling points above their own.
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Many fluoroalkanes, however, go against this trend and have lower melting and boiling points than their nonfluorinated analogues due to the decreased polarizability of fluorine. For example, methane () has a melting point of -182.5 °C whereas tetrafluoromethane () has a melting point of -183.6 °C. As they contain fewer C–H bonds, haloalkanes are less flammable than alkanes, and some are used in fire extinguishers. Haloalkanes are better solvents than the corresponding alkanes because of their increased polarity.
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Condensers with forced-circulation cooling usually employ water as the cooling fluid. The flow may be open, from a tap to a sink, and driven only by the water pressure in the tap. Alternatively, a closed system may be used, in which the water is drawn by a pump from a tank, possibly refrigerated, and returned to it. Water-cooled condensers are suitable for liquids with boiling points well above 0 °C, even higher than 100 °C.
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Glycolic acid is a useful intermediate for organic synthesis, in a range of reactions including: oxidation-reduction, esterification and long chain polymerization. It is used as a monomer in the preparation of polyglycolic acid and other biocompatible copolymers (e.g. PLGA). Commercially, important derivatives include the methyl (CAS# 96-35-5) and ethyl (CAS# 623-50-7) esters which are readily distillable (boiling points 147–149 °C and 158–159 °C, respectively), unlike the parent acid. The butyl ester (b.p.
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Typical laboratory fractional distillation unit For many cases, the boiling points of the components in the mixture will be sufficiently close that Raoult's law must be taken into consideration. Therefore, fractional distillation must be used in order to separate the components by repeated vaporization-condensation cycles within a packed fractionating column. This separation, by successive distillations, is also referred to as rectification. As the solution to be purified is heated, its vapors rise to the fractionating column.
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Some compounds have very high boiling points. To boil such compounds, it is often better to lower the pressure at which such compounds are boiled instead of increasing the temperature. Once the pressure is lowered to the vapor pressure of the compound (at the given temperature), boiling and the rest of the distillation process can commence. This technique is referred to as vacuum distillation and it is commonly found in the laboratory in the form of the rotary evaporator.
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Hexafluoride-forming elements Octahedral structure of SF6 Seventeen elements are known to form binary hexafluorides. Nine of these elements are transition metals, three are actinides, four are chalcogens, and one is a noble gas. Most hexafluorides are molecular compounds with low melting and boiling points. Four hexafluorides (S, Se, Te, and W) are gases at room temperature (25 °C) and a pressure of 1 atm, two are liquids (Re, Mo), and the others are volatile solids.
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The presence of 222Rn has been inferred later from data obtained from the Lunar Prospector alpha particle spectrometer. Radon is found in some petroleum. Because radon has a similar pressure and temperature curve to propane, and oil refineries separate petrochemicals based on their boiling points, the piping carrying freshly separated propane in oil refineries can become radioactive because of decaying radon and its products. Residues from the petroleum and natural gas industry often contain radium and its daughters.
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This page contains tables of azeotrope data for various binary and ternary mixtures of solvents. The data include the composition of a mixture by weight (in binary azeotropes, when only one fraction is given, it is the fraction of the second component), the boiling point (b.p.) of a component, the boiling point of a mixture, and the specific gravity of the mixture. Boiling points are reported at a pressure of 760 mm Hg unless otherwise stated.
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Properties depend on the number and identity of the halogen atoms. In general, the boiling points are even more elevated by combination of halogen atoms because the varying size and charge of different halogens allows more intermolecular attractions. As with fluorocarbons, chlorofluorocarbons and bromofluorocarbons are not flammable: they do not have carbon–hydrogen bonds to react and released halides quench flames. Perfluorodecalin (the trans isomer is shown), a perfluorocarbon that is a liquid at room temperature.
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A log-lin vapor pressure chart for various liquids The higher the vapor pressure of a liquid at a given temperature, the lower the normal boiling point (i.e., the boiling point at atmospheric pressure) of the liquid. The vapor pressure chart to the right has graphs of the vapor pressures versus temperatures for a variety of liquids. As can be seen in the chart, the liquids with the highest vapor pressures have the lowest normal boiling points.
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In most reactions carried out by catalytic distillation, the reactants are often more volatile than the products. Because of this, an internal recycling system, known as the reflux, is implemented right after the condenser (an area within the column where escaped gases are cooled down to liquids). The reflux transfers the concentrated vapor back to the catalyst area. The reflux also returns a portion of the condensed liquids to the column to ensure only the products with the lowest boiling points are captured.
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Condensate out F - Heat exchange G - Condensation collection H - Brine heater MSF Desalination Plant at Jebel Ali G Station, Dubai The plant has a series of spaces called stages, each containing a heat exchanger and a condensate collector. The sequence has a cold end and a hot end while intermediate stages have intermediate temperatures. The stages have different pressures corresponding to the boiling points of water at the stage temperatures. After the hot end there is a container called the brine heater.
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Several shows are made up locally, featuring Romanian music and artists. Some of the most popular shows on the channel are the Romanian version of Total Request Live, Hitlist Romania and Dance Floor Chart. MTV România also showed reality shows mainly American but also local, like Dance Star in 2006. Since its launch, the channel also aired several TV shows and cartoons, like The Osbournes, Yo Momma, Pimp My Ride, Punk'd, Boiling Points, Daria, Beavis and Butt-head, Where My Dogs At?.
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The substitution of hydrogen atoms in an alkane by progressively more fluorine atoms gradually alters several properties: melting and boiling points are lowered, density increases, solubility in hydrocarbons decreases and overall stability increases. Perfluorocarbons, in which all hydrogen atoms are substituted, are insoluble in most organic solvents, reacting at ambient conditions only with sodium in liquid ammonia. The term perfluorinated compound is used for what would otherwise be a perfluorocarbon if not for the presence of a functional group,. often a carboxylic acid.
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Ethylene and oxygen are passed co-currently in a reaction tower at about 130 °C and 400 kPa. The catalyst is an aqueous solution of PdCl2 and CuCl2. The acetaldehyde is purified by extractive distillation followed by fractional distillation. Extractive distillation with water removes the lights ends having lower boiling points than acetaldehyde (chloromethane, chloroethane, and carbon dioxide) at the top, while water and higher-boiling byproducts, such as acetic acid, crotonaldehyde or chlorinated acetaldehydes, are withdrawn together with acetaldehyde at the bottom.
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Fluorinert is the trademarked brand name for the line of electronics coolant liquids sold commercially by 3M. It is an electrically insulating, stable fluorocarbon-based fluid, which is used in various cooling applications. It is mainly used for cooling electronics. Different molecular formulations are available with a variety of boiling points, allowing it to be used in "single- phase" applications, where it remains a liquid, or for "two-phase" applications, where the liquid boils to remove additional heat by evaporative cooling.
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Radon is also found in some petroleum. Because radon has a similar pressure and temperature curve as propane, and oil refineries separate petrochemicals based on their boiling points, the piping carrying freshly separated propane in oil refineries can become partially radioactive due to radon decay particles. Residues from the oil and gas industry often contain radium and its daughters. The sulfate scale from an oil well can be radium rich, while the water, oil, and gas from a well often contains radon.
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High pressures within a reactor provide a driving force for dispersion of radioactive materials from a water-cooled reactor. Molten salt fuels and coolants have boiling points far above the SSR's operating temperature, so its core runs at atmospheric pressure. Physical separation of the steam generating system from the radioactive core by means of a secondary coolant loop eliminates that driving force from the reactor. High pressures within fuel tubes are avoided by venting off fission gases into the surrounding coolant salt.
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Pentanes are some of the primary blowing agents used in the production of polystyrene foam and other foams. Usually, a mixture of n-, i-, and increasingly cyclopentane is used for this purpose. Acid- catalyzed isomerization gives isopentane, which is used in producing high- octane fuels. Because of their low boiling points, low cost, and relative safety, pentanes are used as a working medium in geothermal power stations in some blended refrigerants also used as a working medium in organic rankine cycles.
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Its density is 1.2 g/cm3, which makes it slightly heavier than water. The melting points and boiling points are <25 °C (<77 °F) and 118 °C (244 °F) respectively, although the compound decomposes before reaching the boiling point. The relatively low 0,0004 mmHg (at 20 °C) means Demeton-S-Methyl wil vaporize very slowly and mostly stay as a liquid. Demeton-S-Methyl is less stable than its predecessor Demeton, but it is used instead because of the lower toxicity to humans.
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This cut-away illustrates a model of the interior of Jupiter, with a rocky core overlaid by a deep layer of metallic hydrogen. In planetary science, volatiles are the group of chemical elements and chemical compounds with low boiling points that are associated with a planet's or moon's crust or atmosphere. Examples include nitrogen, water, carbon dioxide, ammonia, hydrogen, methane and sulfur dioxide. In astrogeology, these compounds, in their solid state, often comprise large proportions of the crusts of moons and dwarf planets.
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The Leiden scale probably goes back to around 1894, when Heike Kamerlingh Onnes' cryogenic laboratory was established in Leiden, Netherlands. It has been reportedHubbard, Joanna; Are icebergs made of salt water or fresh water? (April 3, 2000) that the scale is the kelvin scale shifted so that the boiling points of hydrogen and oxygen become zero and 70 respectively, but this is unlikely to be true. Oxygen under a standard atmosphere boils at a temperature in the 90.15 to 90.18 K range.
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Boiling Points is a prank reality television show, much like the format used on Candid Camera. It was broadcast on MTV in the United States from 2004 to 2005. In each half-hour episode, annoying situations were set up and deliberately inflicted on one or more young adults who were unaware that they were being tested. Examples included poor or incompetent customer service in a store or restaurant, being accosted by a date's ex-love-interest while out together, and unprovoked rudeness from a total stranger.
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255–271; On the laboratory scale, PhF is prepared by the thermal decomposition of the benzenediazonium tetrafluoroborate: :PhN2BF4 -> PhF + BF3 \+ N2 According to the procedure, solid [PhN2]BF4 is heated with a flame to initiate an exothermic reaction, which also affords boron trifluoride and nitrogen gas. Product PhF and BF3 are readily separated because of their differing boiling points.. The technical synthesis is by the reaction of cyclopentadiene with difluorocarbene. The initially formed cyclopropane undergoes a ring expansion and subsequent elimination of hydrogen fluoride.
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A racemate is optically inactive, meaning that there is no net rotation of plane-polarized light. Although the two enantiomers rotate plane-polarized light in opposite directions, the rotations cancel because they are present in equal amounts. In contrast to the two pure enantiomers, which have identical physical properties except for the direction of rotation of plane-polarized light, a racemate sometimes has different properties from either of the pure enantiomers. Different melting points are most common, but different solubilities and boiling points are also possible.
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Dippold has appeared as a sketch regular on Late Night with Conan O'Brien and was a cast member on the MTV comedic prank series Boiling Points. In 2006, she became a writer for the twelfth season of MADtv and was also a co-producer during its fourteenth season. In 2009, she joined the writing staff of Parks and Recreation where she worked for several seasons. Dippold wrote the screenplay for the comedic film The Heat (2013), starring Sandra Bullock and Melissa McCarthy, and directed by Paul Feig.
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A few other elements also form similarly volatile hexafluorides, pentafluorides, or heptafluorides. The volatile fluorides can be separated from excess fluorine by condensation, then separated from each other by fractional distillation or selective reduction. Uranium hexafluoride and technetium hexafluoride have very similar boiling points and vapor pressures, which makes complete separation more difficult. Many of the fission products volatilized are the same ones volatilized in non-fluorinated, higher-temperature volatilization, such as iodine, tellurium and molybdenum; notable differences are that technetium is volatilized, but caesium is not.
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Schematic of a simple distillation setup. In simple distillation, the vapor is immediately channeled into a condenser. Consequently, the distillate is not pure but rather its composition is identical to the composition of the vapors at the given temperature and pressure. That concentration follows Raoult's law. As a result, simple distillation is effective only when the liquid boiling points differ greatly (rule of thumb is 25 °C)ST07 Separation of liquid–liquid mixtures (solutions), DIDAC by IUPAC or when separating liquids from non-volatile solids or oils.
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Solar Energy Soc. The efficiency of the cycle is much lower as a result of the lower temperature range, but this can be worthwhile because of the lower cost involved in gathering heat at this lower temperature. Alternatively, fluids can be used that have boiling points above water, and this may have thermodynamic benefits (See, for example, mercury vapour turbine). The properties of the actual working fluid have great influence on the quality of steam (vapour) after the expansion step, influencing the design of the whole cycle.
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By increasing the pressure within the inert gas system, boiling points are increased, allowing reactions under reflux to be carried out at a higher temperature. Also, cannula transfers are accomplished more easily due to the greater gas pressure available to push a liquid reagent from a vessel, through a cannula, into another vessel. Mercury bubblers are avoided where possible, due to the difficulty and expense in dealing with mercury spills. In addition, mercury can react with various chemicals, such as ammonia and acetylenes, with potentially hazardous results.
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The atoms in metals have a strong attractive force between them. Much energy is required to overcome it. Therefore, metals often have high boiling points, with tungsten (5828 K) being extremely high. A remarkable exception is the elements of the zinc group: Zn, Cd, and Hg. Their electron configuration ends in ...ns2 and this comes to resemble a noble gas configuration like that of helium more and more when going down in the periodic table because the energy distance to the empty np orbitals becomes larger.
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R-406A is a refrigerant invented by George H Goble. It is a mixture of three components chlorodifluoromethane (R-22), isobutane (R-600a) and chlorodifluoroethane (R-142b) in the ratio 55/4/41. This refrigerant was designed as a drop-in replacement for R-12 which is compatible with the typical mineral oil lubricants used in R-12 systems. Since it is a zeotropic mixture, it has a range of boiling points which may increase the effectiveness of the heat transfer elements in refrigeration equipment.
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As a common example, salt water boils at a higher temperature than pure water. In other mixtures of miscible compounds (components), there may be two or more components of varying volatility, each having its own pure component boiling point at any given pressure. The presence of other volatile components in a mixture affects the vapor pressures and thus boiling points and dew points of all the components in the mixture. The dew point is a temperature at which a vapor condenses into a liquid.
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Electrostatic forces between particles are strongest when the charges are high, and the distance between the nuclei of the ions is small. In such cases, the compounds generally have very high melting and boiling points and a low vapour pressure. Trends in melting points can be even better explained when the structure and ionic size ratio is taken into account. Above their melting point ionic solids melt and become molten salts (although some ionic compounds such as aluminium chloride and iron(III) chloride show molecule-like structures in the liquid phase).
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A liquid's atmospheric pressure boiling point corresponds to the temperature at which its vapor pressure is equal to the surrounding atmospheric pressure and it is often called the normal boiling point. The higher the vapor pressure of a liquid at a given temperature, the lower the normal boiling point of the liquid. The vapor pressure chart displayed has graphs of the vapor pressures versus temperatures for a variety of liquids. As can be seen in the chart, the liquids with the highest vapor pressures have the lowest normal boiling points.
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Such covalent substances are low-boiling- temperature liquids (such as ethanol), and low-melting-temperature solids (such as iodine and solid CO2). Macromolecular structures have large numbers of atoms linked by covalent bonds in chains, including synthetic polymers such as polyethylene and nylon, and biopolymers such as proteins and starch. Network covalent structures (or giant covalent structures) contain large numbers of atoms linked in sheets (such as graphite), or 3-dimensional structures (such as diamond and quartz). These substances have high melting and boiling points, are frequently brittle, and tend to have high electrical resistivity.
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The bubble point and dew point data would become curved surfaces inside a triangular prism, which connect the three boiling points on the vertical temperature "axes". Each face of this triangular prism would represent a two-dimensional boiling-point diagram for the corresponding binary mixture. Due to their three-dimensional complexity, such boiling-point diagrams are rarely seen. Alternatively, the three- dimensional curved surfaces can be represented on a two-dimensional graph by the use of curved isotherm lines at graduated intervals, similar to iso- altitude lines on a map.
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Subhash C. Basak, Brian D. Gute, and Gregory D. Grunwald (1996): "Estimation of the normal boiling points of haloalkanes using molecular similarity". Croatia Chemica Acta, volume 69, issue 3, pages 1159-1173. Subhash C. Basak, Brian D. Gute, and Gregory D. Grunwald (1996): "A comparative study of topological and geometrical parameters in estimating normal boiling point and octanol/water partition coefficient". Journal of Chemical Information and Computer Science, volume 36, issue 6, pages 1054–1060. Pennetreau, Pascal (1992): "Process for the preparation of 1-chloro-1,1,3,3,3-pentafluoropropane and of 1,1,1,3,3,3-hexafluoropropane".
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Both columns operate under low pressure (55 mm Hg in the first column; 20 mm Hg in the second column) to lower the boiling points of the distillate and bottoms streams, thereby using a lower pressure steam than that for atmospheric columns. At this point, the BioPDO stream has 99% purity. If the BioPDO is to be used for polymer production, however, then greater purity is required. To achieve greater purity, the BioPDO distillate of the second column is sent to a hydrogenation reactor to convert the remaining polymer-coloring impurities into non-coloring chemicals.
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A self-pressurising dewar (silver, foreground) being filled with liquid nitrogen from a large storage tank (white, background). A cryogenic storage dewar (named after James Dewar) is a specialised type of vacuum flask used for storing cryogens (such as liquid nitrogen or liquid helium), whose boiling points are much lower than room temperature. Cryogenic storage dewars may take several different forms including open buckets, flasks with loose-fitting stoppers and self-pressurising tanks. All dewars have walls constructed from two or more layers, with a high vacuum maintained between the layers.
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All these products have wide- ranging boiling points and also different heating values allowing different routes to commercialization and also different uses. The "acidic" elements such as hydrogen sulphide (H2S) and carbon dioxide (CO2), together with oil, mud, water, and mercury, are removed from the gas to deliver a clean sweetened stream of gas. Failure to remove such acidic molecules, mercury, and other impurities could result in damage to the equipment. Corrosion of steel pipes and amalgamization of mercury to aluminium within cryogenic heat exchangers could cause expensive damage.
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On this basis they are estimated to be , respectively. Some experimental evidence suggests astatine may have lower melting and boiling points than those implied by the halogen trend; a chromatographic estimation of the boiling point of elemental astatine in 1982 suggested a boiling point of 503±3 K (about 230±3 °C or 445±5 °F). Astatine sublimes less readily than does iodine, having a lower vapor pressure. Even so, half of a given quantity of astatine will vaporize in approximately an hour if put on a clean glass surface at room temperature.
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The general specification by which early gasolines were measured was that of specific gravity via the Baumé scale and later the volatility (tendency to vaporize) specified in terms of boiling points, which became the primary focuses for gasoline producers. These early eastern crude oil gasolines had relatively high Baumé test results (65 to 80 degrees Baumé) and were called Pennsylvania "High-Test" or simply "High-Test" gasolines. These would often be used in aircraft engines. By 1910, increased automobile production and the resultant increase in gasoline consumption produced a greater demand for gasoline.
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A mixture of constant composition does not have multiple boiling points. An implication of one boiling point is that lighter components never cleanly "boil first". At boiling point, all volatile components boil, but for a component, its percentage in the vapor is the same as its percentage of the total vapor pressure. Lighter components have a higher partial pressure and, thus, are concentrated in the vapor, but heavier volatile components also have a (smaller) partial pressure and necessarily vaporize also, albeit at a lower concentration in the vapor.
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Some compounds have high boiling points as well as being air sensitive. A simple vacuum distillation system as exemplified above can be used, whereby the vacuum is replaced with an inert gas after the distillation is complete. However, this is a less satisfactory system if one desires to collect fractions under a reduced pressure. To do this a "cow" or "pig" adaptor can be added to the end of the condenser, or for better results or for very air sensitive compounds a Perkin triangle apparatus can be used.
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The compounds nitryl fluoride, NO2F, and nitryl chloride, NO2Cl, are not nitronium salts but molecular compounds, as shown by their low boiling points (−72 °C and −6 °C respectively) and short N–X bond lengths (N–F 135 pm, N–Cl 184 pm).F. A. Cotton and G.Wilkinson, Advanced Inorganic Chemistry, 5th edition (1988), Wiley, p.333 Addition of one electron forms the neutral nitryl radical, ; in fact, this is fairly stable and known as the compound nitrogen dioxide. The related negatively charged species is , the nitrite ion.
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Thiele tube A Thiele tube is a glass instrument that is filled with oil that is heated by using an open flame. The sample is placed in the opening in a capillary tube alongside a mercury thermometer and allowed to be heated by the oil as it circulates through the Thiele tube. By using different oils, different temperature ranges can be reached and used to determine melting points. The Thiele tube may also be used to determine boiling points, by using a liquid sample instead of a solid sample.
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His full-page comic strip, "A Day in the Life" (which he also wrote), lambasting celebrity foibles, regularly appeared in US edition throughout his run. His art has been used as props on various television shows including The Drew Carey Show, America's Next Top Model, MTV's Boiling Points, Reno 911!, Nickelodeon's Black History Month, and Late Night with Conan O'Brien. Other clients have included Rolling Stone, Nike, FUBU AT&T;, Village Voice, Time Out, The Source, WWE Magazine, Miami New Times, ESPN The Magazine, AOL and Vibe (Full Commercial Client List).
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A centrifugal evaporator is a device used in chemical and biochemical laboratories for the efficient and gentle evaporation of solvents from many samples at the same time, and samples contained in microtitre plates. If only one sample required evaporation then a rotary evaporator is most often used. The most advanced modern centrifugal evaporators not only concentrate many samples at the same time, they eliminate solvent bumping and can handle solvents with boiling points of up to 220 °C. This is more than adequate for the modern high throughput laboratory.
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Monofluoroalkanes (alkanes with one hydrogen replaced with fluorine) may be chemically and thermally unstable, yet are soluble in many solvents; but as more fluorines are in instead of hydrogens, the stability increases, while melting and boiling points, and solubility decrease. While the densities and viscosities are increased, the dielectric constants, surface tensions, and refractive indices fall. Partially fluorinated alkanes are the hydrofluorocarbons (HFCs). Substituting other halogens in combination with fluorine gives rise to chlorofluorocarbons (CFCs) or bromofluorocarbons (BFCs) and the like (if some hydrogen is retained, HCFCs and the like).
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It is a colorless, volatile liquid at room temperature that is not miscible in water. Being an alkyl chloride, its boiling point varies depending on what kind of halide is attached and where it is attached. The boiling points of chlorides are lower than bromides or iodides due to the small size of chlorine relative to other halogens, and its weaker intermolecular forces. Despite its polarity, 2-chlorobutane is only slightly soluble in water due to the hydrocarbon chain its attached to, this makes it soluble in nonpolar-organic solvents.
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Heat is in effect pumped out of this compartment, through the working gas of the cryocooler and into the compression space. The compression space will be above ambient temperature, and so heat will flow out into the environment. One of their modern uses is in cryogenics and, to a lesser extent, refrigeration. At typical refrigeration temperatures, Stirling coolers are generally not economically competitive with the less expensive mainstream Rankine cooling systems, because they are less energy-efficient. However, below about −40...−30 °C, Rankine cooling is not effective because there are no suitable refrigerants with boiling points this low.
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Mount Cleveland is located from the western end of the Aleutian Arc, a long volcanic chain extending off the coast of Alaska. Containing over 75 volcanoes, this volcanic arc occurs above the subduction zone where the Pacific Plate plunges under the North American plate. As the plate moves deeper into the earth, the increasing pressure results in the loss of volatiles, certain elements and compounds with low boiling points, from various hydrous minerals. One of these compounds is water; its addition to the mantle wedge formed between the subducting and overriding plates lowers the melting point enough to allow magma to form.
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At room temperature, thiophene is a colorless liquid with a mildly pleasant odor reminiscent of benzene, with which thiophene shares some similarities. The high reactivity of thiophene toward sulfonation is the basis for the separation of thiophene from benzene, which are difficult to separate by distillation due to their similar boiling points (4 °C difference at ambient pressure). Like benzene, thiophene forms an azeotrope with ethanol. The molecule is flat; the bond angle at the sulfur is around 93°, the C–C–S angle is around 109°, and the other two carbons have a bond angle around 114°.
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Ethylene glycol Most antifreeze is made by mixing distilled water with additives and a base product – MEG (Mono ethylene glycol) or MPG (Mono propylene glycol). Ethylene glycol solutions became available in 1926 and were marketed as "permanent antifreeze" since the higher boiling points provided advantages for summertime use as well as during cold weather. They are used today for a variety of applications, including automobiles, but there are lower-toxicity alternatives made with propylene glycol available. When ethylene glycol is used in a system, it may become oxidized to five organic acids (formic, oxalic, glycolic, glyoxalic and acetic acid).
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Water with one protium and one deuterium atom occurs naturally in ordinary water in low concentrations (~0.03%) and in far lower amounts (0.000003%) and any such molecules are temporary as the atoms recombine. The most notable physical differences between and , other than the simple difference in specific mass, involve properties that are affected by hydrogen bonding, such as freezing and boiling, and other kinetic effects. This is because the nucleus of deuterium is twice as heavy as protium, and this causes noticeable differences in bonding energies. The difference in boiling points allows the isotopologues to be separated.
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Most of the physical properties of astatine have been estimated (by interpolation or extrapolation), using theoretically or empirically derived methods. For example, halogens get darker with increasing atomic weight – fluorine is nearly colorless, chlorine is yellow-green, bromine is red-brown, and iodine is dark gray/violet. Astatine is sometimes described as probably being a black solid (assuming it follows this trend), or as having a metallic appearance (if it is a metalloid or a metal). The melting and boiling points of astatine are also expected to follow the trend seen in the halogen series, increasing with atomic number.
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Petrol engines may be air-cooled, with fins (to increase the surface area on the cylinders and cylinder head); or liquid- cooled, by a water jacket and radiator. The coolant was formerly water, but is now usually a mixture of water and either ethylene glycol or propylene glycol. These mixtures have lower freezing points and higher boiling points than pure water and also prevent corrosion, with modern antifreezes also containing lubricants and other additives to protect water pump seals and bearings. The cooling system is usually slightly pressurized to further raise the boiling point of the coolant.
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Because this configuration strongly resists removal of an electron, mercury behaves similarly to noble gases, which form weak bonds and hence melt at low temperatures. The stability of the 6s shell is due to the presence of a filled 4f shell. An f shell poorly screens the nuclear charge that increases the attractive Coulomb interaction of the 6s shell and the nucleus (see lanthanide contraction). The absence of a filled inner f shell is the reason for the somewhat higher melting temperature of cadmium and zinc, although both these metals still melt easily and, in addition, have unusually low boiling points.
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Thermogravimetric Analysis (TGA) may be more useful for decomposition behavior determination. Impurities in polymers can be determined by examining thermograms for anomalous peaks, and plasticisers can be detected at their characteristic boiling points. In addition, examination of minor events in first heat thermal analysis data can be useful as these apparently "anomalous peaks" can in fact also be representative of process or storage thermal history of the material or polymer physical aging. Comparison of first and second heat data collected at consistent heating rates can allow the analyst to learn about both polymer processing history and material properties.
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Syngas can be used in the Fischer–Tropsch process to produce diesel, or converted into e.g. methane, methanol, and dimethyl ether in catalytic processes. If the syngas is post-treated by cryogenic processing, it should be taken into account that this technology has great difficulty in recovering pure carbon monoxide if relatively large volumes of nitrogen are present due to carbon monoxide and nitrogen having very similar boiling points which are –191.5 °C and –195.79 °C respectively. Certain process technology selectively removes carbon monoxide by complexation/decomplexation of carbon monoxide with cuprous aluminum chloride () dissolved in an organic liquid such as toluene.
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A cryopump or a "cryogenic pump" is a vacuum pump that traps gases and vapours by condensing them on a cold surface, but are only effective on some gases. The effectiveness depends on the freezing and boiling points of the gas relative to the cryopump's temperature. They are sometimes used to block particular contaminants, for example in front of a diffusion pump to trap backstreaming oil, or in front of a McLeod gauge to keep out water. In this function, they are called a cryotrap, waterpump or cold trap, even though the physical mechanism is the same as for a cryopump.
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Thorium's boiling point of 4788 °C is the fifth-highest among all the elements with known boiling points. The properties of thorium vary widely depending on the degree of impurities in the sample. The major impurity is usually thorium dioxide (ThO2); even the purest thorium specimens usually contain about a tenth of a percent of the dioxide. Experimental measurements of its density give values between 11.5 and 11.66 g/cm3: these are slightly lower than the theoretically expected value of 11.7 g/cm3 calculated from thorium's lattice parameters, perhaps due to microscopic voids forming in the metal when it is cast.
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The system works by lowering the pressure in the centrifuge system - as the pressure drops so does the boiling point of the solvent(s) in the system. When the pressure is sufficiently low that the boiling points of the solvents are below the temperature of the sample holder, then they will boil. This enables solvent to be rapidly removed while the samples themselves are not heated to damaging temperatures. High performance systems can remove very high boiling solvents such as dimethyl sulfoxide (DMSO) or N-methyl-2-pyrrolidone (NMP) while keeping sample temperatures below 40 °C at all times.
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The other 80% may be impurities produced in the manufacturing process and substances created as by products of this process and/or degradation of the drug if improperly stored. When choosing a cutting agent, the drug manufacturer or dealer would ideally attempt to find a chemical that is inexpensive, easy to obtain, relatively non-toxic, and mimics the physical attributes of the drug to be adulterated. For example, if a drug is soluble in water, the preferred adulterant would also be water-soluble. Similar melting and boiling points are also important if the drug is to be smoked.
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Eau Sauvage and L'eau d'Issey (Jaques Cavallier for Issey Miyake) have a large sillage but may be considered much lighter examples of this. Sillage in a perfume could also be considered to be how a fragrance is perceived by others around the wearer and is enhanced by motion, ambient temperature as well as the inherent qualities of the skin. According to an article by Mookerjee, a fragrance is perceived by the diffusion of individual fragrance molecules. The rate of diffusion of these molecules in a fragrance, however, appears to be independent of their molecular weights, boiling points, odour thresholds and odour value.
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The standard boiling point has been defined by IUPAC since 1982 as the temperature at which boiling occurs under a pressure of one bar. The heat of vaporization is the energy required to transform a given quantity (a mol, kg, pound, etc.) of a substance from a liquid into a gas at a given pressure (often atmospheric pressure). Liquids may change to a vapor at temperatures below their boiling points through the process of evaporation. Evaporation is a surface phenomenon in which molecules located near the liquid's edge, not contained by enough liquid pressure on that side, escape into the surroundings as vapor.
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A log-lin vapor pressure chart for various liquids As a general trend, vapor pressures of liquids at ambient temperatures increase with decreasing boiling points. This is illustrated in the vapor pressure chart (see right) that shows graphs of the vapor pressures versus temperatures for a variety of liquids. At the normal boiling point of a liquid, the vapor pressure is equal to the standard atmospheric pressure defined as 1 atmosphere, 760Torr, 101.325kPa, or 14.69595psi. For example, at any given temperature, methyl chloride has the highest vapor pressure of any of the liquids in the chart.
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Depending on when the alcohol is added, either before, during or after fermentation, this can result in a wine with a high alcohol content and noticeable sweetness. ;Foudre : A generic French term for a large wooden vat between 20 and 120 hectoliters. ;Fractions ;The separate parts that are released at different boiling points during the distillation process in the production of Cognac. These include the "heads", "heart" and "tails" with each fractions containing different alcohol levels and flavor compounds ;Free sulfur : The active element of sulfur dioxide that combined with molecules of oxygen to prevent oxidation.
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Vacuum evaporators as a class function because lowering the pressure above a bulk liquid lowers the boiling points of the component liquids in it. Generally, the component liquids of interest in applications of rotary evaporation are research solvents that one desires to remove from a sample after an extraction, such as following a natural product isolation or a step in an organic synthesis. Liquid solvents can be removed without excessive heating of what are often complex and sensitive solvent- solute combinations. Rotary evaporation is most often and conveniently applied to separate "low boiling" solvents such a n-hexane or ethyl acetate from compounds which are solid at room temperature and pressure.
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Distillation is one of the unit operations of chemical engineering. Continuous distillation is used widely in the chemical process industries where large quantities of liquids have to be distilled. Such industries are the natural gas processing, petrochemical production, coal tar processing, liquor production, liquified air separation, hydrocarbon solvents production, cannabinoid separation and similar industries, but it finds its widest application in petroleum refineries. In such refineries, the crude oil feedstock is a very complex multicomponent mixture that must be separated and yields of pure chemical compounds are not expected, only groups of compounds within a relatively small range of boiling points, which are called fractions.
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The vast majority of molecules in a solution are solvent molecules, and most regular solvents are hydrocarbons and so contain NMR-active protons. In order to avoid detecting only signals from solvent hydrogen atoms, deuterated solvents are used where 99+% of the protons are replaced with deuterium (hydrogen-2). The most widely used deuterated solvent is deuterochloroform (CDCl3), although other solvents may be used for various reasons, such as solubility of a sample, desire to control hydrogen bonding, or melting or boiling points. The chemical shifts of a molecule will change slightly between solvents, and the solvent used will almost always be reported with chemical shifts.
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Since slower neutrons are more easily absorbed, the coolant should ideally have a low moderation of neutrons. It is also important that the coolant does not cause excessive corrosion of the structural materials, and that its melting and boiling points are suitable for the reactor's operating temperature. Ideally the coolant should never boil as that would make it more likely to leak out of the system, resulting in a loss- of-coolant accident. Conversely, if the coolant can be prevented from boiling this allows the pressure in the cooling system to remain at neutral levels, and this dramatically reduces the probability of an accident.
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After collaborating with Carol Davila, Istrati pursued his studies for three years at the University of Paris, where he obtained in 1885 a Ph.D. in Chemistry under the direction of Charles Adolphe Wurtz and Charles Friedel, with thesis On colored ethylbenzene and some observations about boiling points in the aromatic series. Statue of Istrati in Carol Park, Bucharest In 1883 he was named Professor of Physics at the School of Bridges and Roads in Bucharest, replacing Emanoil Bacaloglu. On April 1, 1889, Istrati was elected corresponding member of the Romanian Academy. Istrati later became a professor at the University of Bucharest, where he introduced the teaching of organic chemistry.
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The melting and boiling points for a given noble gas are close together, differing by less than ; that is, they are liquids over only a small temperature range. Neon, argon, krypton, and xenon are obtained from air in an air separation unit using the methods of liquefaction of gases and fractional distillation. Helium is sourced from natural gas fields that have high concentrations of helium in the natural gas, using cryogenic gas separation techniques, and radon is usually isolated from the radioactive decay of dissolved radium, thorium, or uranium compounds. Noble gases have several important applications in industries such as lighting, welding, and space exploration.
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Under negative pressure, power for a vacuum source is needed and the reduced boiling points of the distillates requires that the condenser be run cooler to prevent distillate vapors being lost to the vacuum source. Increased cooling demands will often require additional energy and possibly new equipment or a change of coolant. Alternatively, if positive pressures are required, standard glassware can not be used, energy must be used for pressurization and there is a higher chance of side reactions occurring in the distillation, such as decomposition, due to the higher temperatures required to effect boiling. A unidirectional distillation will rely on a pressure change in one direction, either positive or negative.
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Below −203 °C, a low-temperature form exists with a complex structure. Thorium tetrabromide (ThBr4, white, m.p. 679 °C) can be produced either by reacting thorium(IV) hydroxide with hydrobromic acid (which has the disadvantage of often resulting in products contaminated with oxybromides) or by directly reacting bromine or hydrogen bromide with thorium metal or compounds. The product can then be purified by sublimation at 600 °C in a vacuum. The melting and boiling points are 679 °C and 857 °C. Like the tetrachloride, both an α and a β form exist and both are isotypic to the tetrachloride forms, though the phase transition here occurs at 426 °C.
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Thus, the melting and boiling points of bromine are intermediate between those of chlorine and iodine. As a result of the increasing molecular weight of the halogens down the group, the density and heats of fusion and vaporisation of bromine are again intermediate between those of chlorine and iodine, although all their heats of vaporisation are fairly low (leading to high volatility) thanks to their diatomic molecular structure. The halogens darken in colour as the group is descended: fluorine is a very pale yellow gas, chlorine is greenish-yellow, and bromine is a reddish-brown volatile liquid that melts at −7.2 °C and boils at 58.8 °C.
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Fractional distillation is one of the unit operations of chemical engineering. Fractionating columns are widely used in the chemical process industries where large quantities of liquids have to be distilled. Such industries are the petroleum processing, petrochemical production, natural gas processing, coal tar processing, brewing, liquified air separation, and hydrocarbon solvents production and similar industries but it finds its widest application in petroleum refineries. In such refineries, the crude oil feedstock is a complex, multicomponent mixture that must be separated, and yields of pure chemical compounds are not expected, only groups of compounds within a relatively small range of boiling points, also called fractions.
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Each of these formal definitions left the numerical values of the Celsius scale identical to the prior definition to within the limits of accuracy of the metrology of the time. When the melting and boiling points of water ceased being part of the definition, they became measured quantities instead. This is also true of the triple point. In 1948 when the 9th General Conference on Weights and Measures (CGPM) in Resolution 3 first considered using the triple point of water as a defining point, the triple point was so close to being 0.01 °C greater than water's known melting point, it was simply defined as precisely 0.01 °C.
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In 1665 Christiaan Huygens suggested using the melting and boiling points of water as standards, and in 1694 Carlo Renaldini proposed using them as fixed points on a universal scale. In 1701 Isaac Newton proposed a scale of 12 degrees between the melting point of ice and body temperature. Finally in 1724 Daniel Gabriel Fahrenheit produced a temperature scale which now (slightly adjusted) bears his name. He could do this because he manufactured thermometers, using mercury (which has a high coefficient of expansion) for the first time and the quality of his production could provide a finer scale and greater reproducibility, leading to its general adoption.
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As compared to sodium-based liquid metal coolants such as liquid sodium or NaK, lead-based coolants have significantly higher boiling points, meaning a reactor can be operated without risk of coolant boiling at much higher temperatures. This improves thermal efficiency and could potentially allow hydrogen production through thermochemical processes. Lead and LBE also do not react readily with water or air, in contrast to sodium and NaK which ignite spontaneously in air and react explosively with water. This means that lead- or LBE-cooled reactors, unlike sodium-cooled designs, would not need an intermediate coolant loop, which reduces the capital investment required for a plant.
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Both lead and bismuth are also an excellent radiation shield, blocking gamma radiation while simultaneously being virtually transparent to neutrons. In contrast, sodium will form the potent gamma emitter sodium-24 (half-life 15 hours) following intense neutron radiation, requiring a large radiation shield for the primary cooling loop. As heavy nuclei, lead and bismuth can be used as spallation targets for non- fission neutron production, as in Accelerator Transmutation of Waste (see energy amplifier). Both lead-based and sodium-based coolants have the advantage of relatively high boiling points as compared to water, meaning it is not necessary to pressurise the reactor even at high temperatures.
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The melting and boiling points of iron, along with its enthalpy of atomization, are lower than those of the earlier 3d elements from scandium to chromium, showing the lessened contribution of the 3d electrons to metallic bonding as they are attracted more and more into the inert core by the nucleus;Greenwood and Earnshaw, p. 1116 however, they are higher than the values for the previous element manganese because that element has a half- filled 3d subshell and consequently its d-electrons are not easily delocalized. This same trend appears for ruthenium but not osmium. The melting point of iron is experimentally well defined for pressures less than 50 GPa.
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MO diagram of dimolybdenum A sextuple bond is a type of covalent bond involving 12 bonding electrons and in which the bond order is 6. The only known molecules with true sextuple bonds are the diatomic dimolybdenum (Mo2) and ditungsten (W2), which exist in the gaseous phase and have boiling points of and . There is strong evidence to believe that there is no element with atomic number below about 100 that can form a bond with a greater order than 6 between its atoms, but the question of possibility of such a bond between two atoms of different elements remains open. Bonds between heteronuclear systems with two atoms of different elements may not necessarily have the same limit.
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For example, at any given temperature, methyl chloride has the highest vapor pressure of any of the liquids in the chart. It also has the lowest normal boiling point (−24.2 °C), which is where the vapor pressure curve of methyl chloride (the blue line) intersects the horizontal pressure line of one atmosphere (atm) of absolute vapor pressure. Note that at higher altitudes, the atmospheric pressure is less than that at sea level, so boiling points of liquids are reduced. At the top of Mount Everest, the atmospheric pressure is approximately 0.333 atm, so by using the graph, the boiling point of diethyl ether would be approximately 7.5 °C versus 34.6 °C at sea level (1 atm).
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The equivalence of power laws with a particular scaling exponent can have a deeper origin in the dynamical processes that generate the power-law relation. In physics, for example, phase transitions in thermodynamic systems are associated with the emergence of power-law distributions of certain quantities, whose exponents are referred to as the critical exponents of the system. Diverse systems with the same critical exponents—that is, which display identical scaling behaviour as they approach criticality—can be shown, via renormalization group theory, to share the same fundamental dynamics. For instance, the behavior of water and CO2 at their boiling points fall in the same universality class because they have identical critical exponents.
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For two particular volatile components at a certain pressure such as atmospheric pressure, a boiling-point diagram shows what vapor (gas) compositions are in equilibrium with given liquid compositions depending on temperature. In a typical binary boiling- point diagram, temperature is plotted on a vertical axis and mixture composition on a horizontal axis. Boiling-point diagram A simple example diagram with hypothetical components 1 and 2 in a non-azeotropic mixture is shown at right. The fact that there are two separate curved lines joining the boiling points of the pure components means that the vapor composition is usually not the same as the liquid composition the vapor is in equilibrium with.
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In catalytic reforming, a mixture of hydrocarbons with boiling points between 60–200 °C is blended with hydrogen gas and then exposed to a bifunctional platinum chloride or rhenium chloride catalyst at 500–525 °C and pressures ranging from 8–50 atm. Under these conditions, aliphatic hydrocarbons form rings and lose hydrogen to become aromatic hydrocarbons. The aromatic products of the reaction are then separated from the reaction mixture (or reformate) by extraction with any one of a number of solvents, including diethylene glycol or sulfolane, and benzene is then separated from the other aromatics by distillation. The extraction step of aromatics from the reformate is designed to produce aromatics with lowest non-aromatic components.
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During the 1970s, researchers developed the sealed version or gel battery, which mixes a silica gelling agent into the electrolyte (silica gel- based lead–acid batteries used in portable radios from the early 1930s were not fully sealed). This converts the formerly liquid interior of the cells into a semi-stiff paste, providing many of the same advantages of the AGM. Such designs are even less susceptible to evaporation and are often used in situations where little or no periodic maintenance is possible. Gel cells also have lower freezing and higher boiling points than the liquid electrolytes used in conventional wet cells and AGMs, which makes them suitable for use in extreme conditions.
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Since then, Fourier transform infrared spectroscopy (FTIR) instruments have become critical in the forensic analysis of unknown material because they are nondestructive and extremely quick to use. Spectroscopy was further advanced in 1955 with the invention of the modern atomic absorption (AA) spectrophotometer by Alan Walsh. AA analysis can detect specific elements that make up a sample along with their concentrations, allowing for the easy detection of heavy metals such as arsenic and cadmium. Advancements in the field of chromatography arrived in 1953 with the invention of the gas chromatograph by Anthony T. James and Archer John Porter Martin, allowing for the separation of volatile liquid mixtures with components which have similar boiling points.
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In contrast with volatiles, elements and compounds with high boiling points are known as refractory substances. Planetary scientists often classify volatiles with exceptionally low melting points, such as hydrogen and helium, as gases (as in gas giant), whereas those volatiles with melting points above about 100 K (–173 °C, –280 °F) are referred to as ices. The terms "gas" and "ice" in this context can apply to compounds that may be solids, liquids or gases. Thus, Jupiter and Saturn are gas giants, and Uranus and Neptune are ice giants, even though the vast majority of the "gas" and "ice" in their interiors is a hot, highly dense fluid that gets denser as the center of the planet is approached.
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This graph invariant was introduced by Haruo Hosoya in 1971.. It is often used in chemoinformatics for investigations of organic compounds..Internet Electronic Journal of Molecular Design, special issues dedicated to Professor Haruo Hosoya on the occasion of the 65th birthday: Volume 1 (2002), Number 9 — Volume 2 (2003), Number 6. In his article, "The Topological Index Z Before and After 1971," on the history of the notion and the associated inside stories, Hosoya writes that he introduced the Z index to report a good correlation of the boiling points of alkane isomers and their Z indices, basing on his unpublished 1957 work carried out while he was an undergraduate student at the University of Tokyo.
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This allows them to occasionally boil off their surfaces and then fall again as snow, whereas compounds with higher boiling points would remain solid. The relative abundances of these three compounds in the largest KBOs is directly related to their surface gravity and ambient temperature, which determines which they can retain. Water ice has been detected in several KBOs, including members of the Haumea family such as , mid-sized objects such as 38628 Huya and 20000 Varuna, and also on some small objects. The presence of crystalline ice on large and mid-sized objects, including 50000 Quaoar where ammonia hydrate has also been detected, may indicate past tectonic activity aided by melting point lowering due to the presence of ammonia.
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Liquid air has a density of approximately 870 kg/m3 (0.87 g/cm3), though the density may vary depending on the elemental composition of the air. Since dry gaseous air contains approximately 78% nitrogen, 21% oxygen, and 1% argon, the density of liquid air at standard composition is calculated by the percentage of the components and their respective liquid densities (see liquid nitrogen and liquid oxygen). Although air contains trace amounts of carbon dioxide (about 0.040%), carbon dioxide solidifies from the gas phase without passing through the intermediate liquid phase, and hence will not be present in liquid air at pressures less than 5.1 atmospheres. The boiling point of liquid air is -194.35 °C (78.80 K), intermediate between the boiling points of liquid nitrogen and liquid oxygen.
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They found that the black one (which turned out to be the superconductor) had the composition YBa2Cu3O7−δ. The article reporting this material led to rapid discovery of several new high-temperature superconducting materials, ushering in a new era in material science and chemistry. YBCO was the first material found to become superconducting above 77 K, the boiling point of liquid nitrogen. All materials developed before 1986 became superconducting only at temperatures near the boiling points of liquid helium (Tb = 4.2 K) or liquid hydrogen (Tb = 20.3 K) — the highest being Nb3Ge at 23 K. The significance of the discovery of YBCO is the much lower cost of the refrigerant used to cool the material to below the critical temperature.
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There are some parallels between the chemistry of ammonia NH3 and water H2O. For example, the capacity of both compounds to be protonated to give NH4+ and H3O+ or deprotonated to give NH2− and OH−, with all of these able to be isolated in solid compounds. Nitrogen shares with both its horizontal neighbours a preference for forming multiple bonds, typically with carbon, oxygen, or other nitrogen atoms, through pπ–pπ interactions. Thus, for example, nitrogen occurs as diatomic molecules and therefore has very much lower melting (−210 °C) and boiling points (−196 °C) than the rest of its group, as the N2 molecules are only held together by weak van der Waals interactions and there are very few electrons available to create significant instantaneous dipoles.
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The violent effects of thermite Thermite usage is hazardous due to the extremely high temperatures produced and the extreme difficulty in smothering a reaction once initiated. Small streams of molten iron released in the reaction can travel considerable distances and may melt through metal containers, igniting their contents. Additionally, flammable metals with relatively low boiling points such as zinc (with a boiling point of 907 °C, which is about 1,370 °C below the temperature at which thermite burns) could potentially spray superheated boiling metal violently into the air if near a thermite reaction. If, for some reason, thermite is contaminated with organics, hydrated oxides and other compounds able to produce gases upon heating or reaction with thermite components, the reaction products may be sprayed.
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Because of its closed-shell electron configuration, its density and melting and boiling points differ significantly from those of most other lanthanides. In 1878, the Swiss chemist Jean Charles Galissard de Marignac separated from the rare earth "erbia" another independent component, which he called "ytterbia", for Ytterby, the village in Sweden near where he found the new component of erbium. He suspected that ytterbia was a compound of a new element that he called "ytterbium" (in total, four elements were named after the village, the others being yttrium, terbium, and erbium). In 1907, the new earth "lutecia" was separated from ytterbia, from which the element "lutecium" (now lutetium) was extracted by Georges Urbain, Carl Auer von Welsbach, and Charles James.
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Mercury-in-glass thermometer Thermometers can be calibrated either by comparing them with other calibrated thermometers or by checking them against known fixed points on the temperature scale. The best known of these fixed points are the melting and boiling points of pure water. (Note that the boiling point of water varies with pressure, so this must be controlled.) The traditional way of putting a scale on a liquid-in-glass or liquid-in-metal thermometer was in three stages: #Immerse the sensing portion in a stirred mixture of pure ice and water at atmospheric pressure and mark the point indicated when it had come to thermal equilibrium. #Immerse the sensing portion in a steam bath at Standard atmospheric pressure and again mark the point indicated.
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TiCl4 is a dense, colourless distillable liquid, although crude samples may be yellow or even red-brown. It is one of the rare transition metal halides that is a liquid at room temperature, VCl4 being another example. This property reflects the fact that molecules of TiCl4 weakly self-associate. Most metal chlorides are polymers, wherein the chloride atoms bridge between the metals. Its melting and boiling points are similar to those of CCl4. Ti4+ has a "closed" electronic shell, with the same number of electrons as the inert gas argon. The tetrahedral structure for TiCl4 is consistent with its description as a d0 metal center (Ti4+) surrounded by four identical ligands. This configuration leads to highly symmetrical structures, hence the tetrahedral shape of the molecule.
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The separation method that EI is usually coupled with is gas chromatography (GC), where in GC the particles are separated by their boiling points and polarity, followed by solvent extraction of the samples collected on the filters. An alternative to solvent-based extraction for particulates on filters is the use of thermal extraction (TE)-GC/MS, which utilizes oven interfaced with the GC inlet to vaporize the analyte of the sample and into the GC inlet. This technique is more often used then solvent-based extraction, because of its better sensitivity, eliminates need for solvents, and can be fully automated. To increase the separation of the particles the GC can be coupled with a time of flight (TOF)-MS, which is a mass separation method that separates ions based on their size.
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This arrangement is thus energetically extremely stable for all these particles, and this stability accounts for many crucial facts regarding helium in nature. For example, the stability and low energy of the electron cloud state in helium accounts for the element's chemical inertness, and also the lack of interaction of helium atoms with each other, producing the lowest melting and boiling points of all the elements. In a similar way, the particular energetic stability of the helium-4 nucleus, produced by similar effects, accounts for the ease of helium-4 production in atomic reactions that involve either heavy-particle emission or fusion. Some stable helium-3 (2 protons and 1 neutron) is produced in fusion reactions from hydrogen, but it is a very small fraction compared to the highly favorable helium-4.
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Conversely, the chloride ion is a weaker reducing agent than bromide, but a stronger one than fluoride. It is intermediate in atomic radius between fluorine and bromine, and this leads to many of its atomic properties similarly continuing the trend from iodine to bromine upward, such as first ionisation energy, electron affinity, enthalpy of dissociation of the X2 molecule (X = Cl, Br, I), ionic radius, and X–X bond length. (Fluorine is anomalous due to its small size.) All four stable halogens experience intermolecular van der Waals forces of attraction, and their strength increases together with the number of electrons among all homonuclear diatomic halogen molecules. Thus, the melting and boiling points of chlorine are intermediate between those of fluorine and bromine: chlorine melts at −101.0 °C and boils at −34.0 °C.
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The primary disadvantages of Fischer esterification routes are its thermodynamic reversibility and relatively slow reaction rates—often on the scale of several hours to years, depending on the reaction conditions. Workarounds to this can be inconvenient if there are other functional groups sensitive to strong acid, in which case other catalytic acids may be chosen. If the product ester has a lower boiling point than either water or the reagents, the product may be distilled rather than water; this is common as esters with no protic functional groups tend to have lower boiling points than their protic parent reagents. Purification and extraction are easier if the ester product can be distilled away from the reagents and byproducts, but reaction rate can be slowed because overall reaction temperature can be limited in this scenario.
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As evidence it has been shown that flies can differentiate between two odor molecules which only differ in hydrogen isotope (which will drastically change vibrational energy levels of the molecule). Not only could the flies distinguish between the deuterated and non-deuterated forms of an odorant, they could generalise the property of "deuteratedness" to other novel molecules. In addition, they generalised the learned avoidance behaviour to molecules which were not deuterated but did share a significant vibration stretch with the deuterated molecules, a fact which the differential physics of deuteration (below) has difficulty in accounting for. Deuteration changes the heats of adsorption and the boiling and freezing points of molecules (boiling points: 100.0 °C for H2O vs. 101.42 °C for D2O; melting points: 0.0 °C for H2O, 3.82 °C for D2O), pKa (i.e.
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Titan's theorized internal structure, subsurface ocean shown in blue A biosphere based on ammonia would likely exist at temperatures or air pressures that are extremely unusual in relation to life on Earth. Life on Earth usually exists within the melting point and boiling point of water at normal pressure, between 0 °C (273 K) and 100 °C (373 K); at normal pressure ammonia's melting and boiling points are between −78 °C (195 K) and −33 °C (240 K). Chemical reactions generally proceed more slowly at a lower temperature. Therefore, ammonia-based life, if it exists, might metabolize more slowly and evolve more slowly than life on Earth. On the other hand, lower temperatures could also enable living systems to use chemical species that would be too unstable at Earth temperatures to be useful.
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Industrial distillation is typically performed in large, vertical cylindrical columns known as distillation towers or distillation columns with diameters ranging from about 65 centimeters to 16 meters and heights ranging from about 6 meters to 90 meters or more. When the process feed has a diverse composition, as in distilling crude oil, liquid outlets at intervals up the column allow for the withdrawal of different fractions or products having different boiling points or boiling ranges. The "lightest" products (those with the lowest boiling point) exit from the top of the columns and the "heaviest" products (those with the highest boiling point) exit from the bottom of the column and are often called the bottoms. Diagram of a typical industrial distillation tower Industrial towers use reflux to achieve a more complete separation of products.
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Devil's venom was a nickname coined by Soviet rocket scientists for a liquid rocket fuel composed of a dangerous combination of nitric acid and hydrazine—specifically, hypergolic UDMH-nitric acid. Both propellants are extremely dangerous, nitric acid is highly corrosive, and the type used gives off nitrogen dioxide, while UDMH is toxic and carcinogenic, but is used in rocketry because this combination of fuel and oxidizer is hypergolic (it does not require an external ignition source), which makes rockets using these materials simpler. Further, both the fuel and oxidizer have high boiling points compared to other rocket fuels such as liquid hydrogen, and oxidizers such as liquid oxygen, allowing rockets to be stored ready for launch for long periods without the fuel or oxidizer boiling off and needing to be replenished.
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Greenwood and Earnshaw, pp. 420–4 Over twenty other hydrides of nitrogen are known, the most important being hydrazine (N2H4) and hydrogen azide (HN3). Hydrazine has physical properties that are remarkably similar to those of water: its melting and boiling points are 2.0 °C and 113.5 °C, the density of the solid at −5 °C is 1.146 g/cm3, while that of the liquid at 25 °C is 1.00 g/cm3.Greenwood and Earnshaw, pp. 426–7 The azanes are a series which include ammonia, hydrazine and triazane. Phosphine, a toxic, colourless gas, is the most stable phosphorus hydride and is the first of the homologous straight-chain polyphosphane series PnHn+2 (n = 1–9) that become increasingly thermally unstable as n increases. Other cyclic and condensed polyphosphane series are known, from PnHn to PnHn−18, amounting to 85 known phosphanes in 1997.
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The melting point of iron is experimentally well defined for pressures less than 50 GPa. For greater pressures, published data (as of 2007) put the γ-ε-liquid triple point at pressures that differ by tens of gigapascals and 1000 K in the melting point. Generally speaking, molecular dynamics computer simulations of iron melting and shock wave experiments suggest higher melting points and a much steeper slope of the melting curve than static experiments carried out in diamond anvil cells. The melting and boiling points of iron, along with its enthalpy of atomization, are lower than those of the earlier group 3d elements from scandium to chromium, showing the lessened contribution of the 3d electrons to metallic bonding as they are attracted more and more into the inert core by the nucleus;Greenwood and Earnshaw, p.
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The melting point of a substance is the point where it changes state from solid to liquid while the boiling point of a substance (in liquid state) is the point where the vapour pressure of the liquid equals the environmental pressure surrounding the liquid Section 17.43, page 321 and all the liquid changes state to gas. As a metal is heated to its melting point, the metallic bonds keeping the atoms in place weaken so that the atoms can move around, and the metallic bonds eventually break completely at the metal's boiling point. Therefore, the falling melting and boiling points of the alkali metals indicate that the strength of the metallic bonds of the alkali metals decreases down the group. This is because metal atoms are held together by the electromagnetic attraction from the positive ions to the delocalised electrons.
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Craft's investigations were largely in the field of organic chemistry, but his name is connected also with many interesting achievements in physics and in physical chemistry. He invented a new hydrogen thermometer; measured the densities of iodine at very high temperatures; demonstrated an interesting regularity in the variation of the boiling points of chemically allied substances with the external pressure; prepared a number of new compounds of the element silicon, which are interesting because of their chemical resemblance to the corresponding compounds of carbon; and also prepared new compounds of arsenic. But his most important achievement was the discovery, jointly with Friedel, of one of the most fruitful synthetic methods in organic chemistry, the Friedel–Crafts reaction. Hundreds of new carbon compounds have been brought into existence by this method (New International Encyclopedia), which is based on the catalytic action of the chloride of aluminium.
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This arrangement is thus energetically extremely stable for all these particles, and this stability accounts for many crucial facts regarding helium in nature. For example, the stability and low energy of the electron cloud of helium causes helium's chemical inertness (the most extreme of all the elements), and also the lack of interaction of helium atoms with each other (producing the lowest melting and boiling points of all the elements). In a similar way, the particular energetic stability of the helium-4 nucleus, produced by similar effects, accounts for the ease of helium-4 production in atomic reactions involving both heavy-particle emission and fusion. Some stable helium-3 is produced in fusion reactions from hydrogen, but it is a very small fraction, compared with the highly energetically favorable production of helium-4. The stability of helium-4 is the reason that hydrogen is converted to helium-4, and not deuterium (hydrogen-2) or helium-3 or other heavier elements during fusion reactions in the Sun.
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He examined and reported on the auriferous (gold-bearing) rivers, the turquoise mines, the forests and the fossil beds of France. He devised the method of tinning iron that is still employed, and investigated the differences between iron and steel, correctly showing that the amount of carbon is greatest in cast iron, less in steel, and least in wrought iron. His book on this subject (1722) was translated into English and German. He was noted for a thermometer he constructed on the principle of taking the freezing point of water as 0°, and graduating the tube into degrees each of which was one-thousandth of the volume contained by the bulb and tube up to the zero mark. It was an accident dependent on the particular alcohol employed which made the boiling-point of water 80°; mercurial thermometers graduated into 80 equal parts between the freezing- and boiling-points of water are named Réaumur thermometers but diverge from his design and intention.
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At the start of period 7, from francium to thorium, the melting points of the elements increase (as in other periods), because the number of delocalised electrons each atom contributes increases from one in francium to four in thorium, leading to greater attraction between these electrons and the metal ions as their charge increases from one to four. After thorium, there is a new downward trend in melting points from thorium to plutonium, where the number of f electrons increases from about 0.4 to about 6: this trend is due to the increasing hybridisation of the 5f and 6d orbitals and the formation of directional bonds resulting in more complex crystal structures and weakened metallic bonding. (The f-electron count for thorium metal is a non-integer due to a 5f–6d overlap.) Among the actinides up to californium, which can be studied in at least milligram quantities, thorium has the highest melting and boiling points and second-lowest density; only actinium is lighter.
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In the previous elements, the energetic cost of promoting an electron to the next higher energy level is too great to compensate for that released by lessening inter-electronic repulsion. However, in the 3d transition metals, the energy gap between the 3d and the next-higher 4s subshell is very small, and because the 3d subshell is more compact than the 4s subshell, inter-electron repulsion is smaller between 4s electrons than between 3d electrons. This lowers the energetic cost of promotion and increases the energy released by it, so that the promotion becomes energetically feasible and one or even two electrons are always promoted to the 4s subshell. (Similar promotions happen for every transition metal atom but one, palladium.) Chromium is the first element in the 3d series where the 3d electrons start to sink into the inert core; they thus contribute less to metallic bonding, and hence the melting and boiling points and the enthalpy of atomisation of chromium are lower than those of the preceding element vanadium.
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