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hydrocarbons

hydrocarbons Sentence Examples

  • It readily condenses with aromatic hydrocarbons in the presence of sulphuric acid.

  • In order to obtain the phenol from this distillate, it is treated with caustic soda, which dissolves the phenol and its homologues tegether with a certain quantity of naphthalene and other hydrocarbons.

  • The solution is diluted with water, and the hydrocarbons are thereby precipitated and separated.

  • This heat of formation, like that of most hydrocarbons, is comparatively small: the heat of formation of saturated hydrocarbons is always positive, but the heat of formation of unsaturated hydrocarbons is frequently negative.

  • The calorific power of Baku oil appears to be highest, while this oil is poorest in solid hydrocarbons, of which the American petroleums contain moderate quantities, and the Upper Burma oils the largest amount.

  • The principal elements are found in various combinations, the hydrocarbons of the Pennsylvania oils being mainly paraffins (q.v.), while those of Caucasian petroleum belong for the most part to the naphthenes, isomeric with the olefines (q.v.).

  • Certain crude oils have also been found to contain camphenes, naphthalene and other aromatic hydrocarbons.

  • The " cracking " process, whereby a considerable quantity of the oil which is intermediate between kerosene and lubricating oil is converted into hydrocarbons of lower specific gravity and boiling-point suitable for illuminating purposes, is one of great scientific and technical interest.

  • It is generally understood that the products of fractional distillation, even in the laboratory, are not identical with the hydrocarbons present in the crude oil, but are in part produced by the action of heat upon them.

  • They found that the paraffin was thus converted, with the evolution of but little gas, into hydrocarbons which were liquid at ordinary temperatures.

  • In an experiment on 3500 grams of paraffin produced from shale (melting point 44'5° C.) they obtained nearly 4 litres of liquid hydrocarbons, which they subjected to fractional distillation, and on examining the fraction distilling below loo° C., they found it to consist mainly of olefines.

  • The result of this treatment is that the comparatively heavy oils undergo dissociation, as shown by the experiments of Thorpe and Young, into specifically lighter hydrocarbons of lower boiling points, and the yield of kerosene from ordinary crude petroleum may thus be greatly increased.

  • Under such conditions, distillation takes place at higher temperatures than the normal boiling-points of the constituent hydrocarbons of the oil, and a partial cracking results.

  • In the American petroleum refineries it is found that sufficient cracking can be produced by slow distillation in stills of which the upper part is sufficiently cool to allow of the condensation of the vapours of the less volatile hydrocarbons, the condensed liquid thus falling back into the heated body of oil.

  • The rationale of this treatment is not fully understood, but the action appears to consist in the separation or decomposition of the aromatic hydrocarbons, fatty and other acids, phenols, tarry bodies, &c., which lower the quality of the oil, the sulphuric acid removing some, while the caustic soda takes out the remainder, and neutralizes the acid which has been left in the oil.

  • In France, the standard is 35° C. (Granier tester, equivalent to 98° F.), and according to their flashpoint, liquid hydrocarbons are divided into two classes (below and above 35° C.), considered differently in regard to quantities storable and other regulations.

  • A consequence of this empirical division was that marsh gas, ethylene and cyanogen were regarded as inorganic, and at a later date many other hydrocarbons of undoubtedly organic nature had to be included in the same division.

  • Taking as types hydrogen, hydrochloric acid, water and ammonia, he postulated that all organic compounds were referable to these four forms: the hydrogen type included hydrocarbons, aldehydes and ketones; the hydrochloric acid type, the chlorides, bromides and iodides; the water type, the alcohols, ethers, monobasic acids, acid anhydrides, and the analogous sulphur compounds; and the ammonia type, the amines, acid-amides, and the analogous phosphorus and arsenic compounds.

  • An apt definition of organic chemistry is that it is "the study of the hydrocarbons and their derivatives."

  • This description, although not absolutely comprehensive, serves as a convenient starting-point for a preliminary classification, since a great number of substances, including the most important, are directly referable to hydrocarbons, being formed by replacing one or more hydrogen atoms by other atoms or groups.

  • Let us now consider hydrocarbons containing 2 atoms of carbon.

  • Hydrocarbons containing any number of double or triple linkages, as well as both double and triple linkages, are possible, and a considerable number of such compounds have been prepared.

  • From n-butane we may derive, by a similar substitution of methyl groups, the two hydrocarbons: (I) CH 3 CH 2 CH 2 CH 2 CH 3, and (2) CH 3.

  • These three hydrocarbons are isomeric, i.e.

  • (methylene) groups and the molecule consists of a single chain; such hydrocarbons are referred to as being normal; (2) has a branch and contains the group; CH (methine) in which the free valencies are attached to carbon atoms; such hydrocarbons are termed secondary or iso-; (3) is characterized by a carbon atom linked directly to four other carbon atoms; such hydrocarbons are known as tertiary.

  • Deferring the detailed discussion of cyclic or ringed hydrocarbons, a correlation of the various types or classes of compounds which may be derived from hydrocarbon nuclei will now be given.

  • It is convenient first to consider the effect of introducing one, two, or three hydroxyl (OH) groups into the - CH 3, > CH 2, and >CH groups, which we have seen to characterize the different types of hydrocarbons.

  • Cyclic Hydrocarbons and Nuclei.

  • By fusing two nuclei we obtain the formula of naphthalene, C 1 oH 8; by fusing three, the hydrocarbons anthracene and phenanthrene, C14H10; by fusing four, chrysene, C18H12, and possibly pyrene, C16H1n; by fusing five, picene, C22 H 14.

  • This and other facts connected with the stability of benzenoid compounds are clearly shown when we consider mixed aliphatic-aromatic hydrocarbons, i.e.

  • Thomsen then investigated heats of combustion of various benzenoid hydrocarbons - benzene, naphthalene, anthracene, phenanthrene, &c. - in the crystallized state.

  • But, at the same time, the constants in the above relation are not identical with those in the corresponding relation empirically deduced from observations on fatty hydrocarbons; and we are therefore led to conclude that a benzene union is considerably more stable than an ethylene union.

  • These isomeric hydrocarbons, of the formula C14H10, are to be regarded as formed by the fusion of three.

  • An ethylenic or double carbon union in the aliphatic hydrocarbons has, apparently, the same effect on the boiling-point as two hydrogen atoms, since the compounds C 0 H 2 „ +2 and CoH2n boil at about the same temperature.

  • The same difference attends the introduction of the methyl group into many classes of compounds, for example, the paraffins, olefines, acetylenes, aromatic hydrocarbons, alcohols, aldehydes, ketones and esters, while a slightly lower value (157.1) is found in the case of the halogen compounds, nitriles, amines, acids, ethers, sulphides and nitro compounds.

  • It contains four independent constants; two of these may be calculated from the heats of combustion of saturated hydrocarbons, and the other two from the combustion of hydrocarbons containing double and triple linkages.

  • A more complex chromophoric group is the triple ethylenic grouping: C > C =, the introduction of which was rendered necessary by the discovery of certain coloured hydrocarbons.

  • As a general rule, hydrocarbons are colourless; the exceptions include the golden yellow acenaphthylene, the red bidiphenylene-ethylene, and the derivatives of fulvene CH: CH >CH 2, which have been discussed by CH: CH J.

  • Hydrocarbons of similar structure have been prepared by Thiele, for example, the orange-yellow tetraphenyl-para-xylylene, which is obtained by boiling the bromide C6H4[CBr(C6H5)2]2 with benzene and molecular silver.

  • When solid caoutchouc is strongly heated it breaks down, without change in its ultimate composition, into a number of simpler liquid hydrocarbons of the terpene class (dipentene, di-isoprene, isoprene, &c.), of which one, isoprene (C5H8), is of simpler structure than oil of turpentine (C 10 H 16), from which it can also be obtained by the action of an intense heat.

  • At higher temperatures the viscous liquid suffers decomposition with the formation of various liquid hydrocarbons, principally members of the terpene series.

  • Schultz, Ann., 1879, 196, p. 35); or the two hydrocarbons may be separated by carbon bisulphide, in which anthracene is insoluble.

  • Secondary reactions take place at the same time, yielding more particularly hydrocarbons of the paraffin series.

  • The nitro compounds of the lower members of the paraffin series cannot be prepared by the direct action of nitric acid on the hydrocarbons themselves, but, in the case of some of the higher members of the series direct nitration is possible (M.

  • Berthelot, and shown to be very fruitful in forming hydrocarbons.

  • It is convenient to distinguish between aliphatic and aromatic acids; the first named being derived from open-chain hydrocarbons, the second from ringed hydrocarbon nuclei.

  • Dibasic acids of the paraffin series of hydrocarbons have the general formula C n H 2 (000H) 2 "; malonic and succinic acids are important members.

  • Other reactions which introduce carboxyl groups into aromatic groups are: the action of carbonyl chloride on aromatic hydrocarbons in the presence of aluminium chloride, acid-chlorides being formed which are readily decomposed by water to give the acid; the action of urea chloride Cl�CO�NH 2, cyanuric acid (CONH) 3, nascent cyanic acid, or carbanile on hydrocarbons in the presence of aluminium chloride, acid-amides being obtained which are readily decomposed to give the acid.

  • An important oxidation synthesis of aromatic acids is from hydrocarbons with aliphatic side chains; thus toluene, or methylbenzene, yields benzoic acid, the xylenes, or dimethyl-benzene, yield methyl-benzoic acids and phthalic acids.

  • It dissolves most organic compounds, resins, hydrocarbons, fatty acids and many metallic salts, sometimes forming, in the latter case, crystalline compounds in which the ethyl alcohol plays a role similar to that of water of crystallization.

  • The action is not properly understood; it may be due to the reducing gases (hydrogen, hydrocarbons, &c.) which are invariably present in wood charcoal.

  • Hydrocarbons, such as petroleum, bitumen, paraffin, &c., are also found occasionally in coal, but more generally in the associated sandstones and limestones of the Carboniferous formation.

  • p This term is founded on a misapprehension of the nature of the occurrence, since, although the softening takes place at a low temperature, still it marks the point at which destructive distillation commences, and hydrocarbons both of a solid and gaseous character are formed.

  • Bone has shown that when exposed for some time to the sun's rays it undergoes certain polymerization changes which lead to the deposition of a film of heavy hydrocarbons on the surface of the tube.

  • The earlier papers deal chiefly with the properties and modes of synthesis of cloud chain hydrocarbons and their derivatives.

  • OLEFINE, in organic chemistry, the generic name given to open chain hydrocarbons having only singly and doubly linked pairs of carbon atoms. The word is derived from the French olefiant (from olefier, to make oil), which was the name given to ethylene, the first member of the series, by the Dutch chemists, J.

  • It is further purified by heating in closed vessels, but even then it still contains a certain amount of mineral matter and more or less hydrocarbons.

  • It may be condensed to a liquid, which boils at 8° C. It is readily soluble in benzene, glacial acetic acid, and in many hydrocarbons.

  • The para or true quinones are obtained by the oxidation of hydrocarbons with chromic acid or of various para di-derivatives of benzene with chromic acid mixture, such, for example, as para-aminophenol, para-phenylene diamine, paraa.minoazobenzene, &c. H.

  • It is only very sparingly soluble in water, but dissolves readily in solutions of the alkaline iodides and in alcohol, ether, carbon bisulphide, chloroform, and many liquid hydrocarbons.

  • They may be prepared by the oxidation of secondary alcohols; by the addition of the elements of water to hydrocarbons of the acetylene type RC CH; by oxidation of primary alcohols of the type RR' CH CH 2 OH:RR' CH CH 2 OH --> R CO R'+H20+H2C02; by distillation of the calcium salts of the fatty acids, C.H2.02; by heating the sodium salts of these acids CnH2n02 with the corresponding acid anhydride to 190 C. (W.

  • Considering the hydrocarbons given by the general formula C x H y, the internal linkages of the carbon atoms need at least xi bonds, using up 2(xI) valencies of the 4x to be accounted for, and thus leaving no more than 2(x-11) for binding hydrogen: a compound C 3 H 9 is therefore impossible, and indeed has never been met.

  • that of the alcohols, which only differ from the hydrocarbons by having a group OH, called hydroxyl, instead of H, hydrogen; these compounds, when derived from the above methane series of hydrocarbons, are expressed by the general formula C7,H27,+10H.

  • It is therefore more probably due to metallic oxides than to hydrocarbons.

  • Other authors have sought the origin of the diamond in the action of the hydrated magnesian silicates on hydrocarbons derived from bituminous schists, or in the decomposition of metallic carbides.

  • Adolf Knop suggested that this may have first yielded hydrocarbons by contact with water, and that from these the crystalline diamond has been formed.

  • Minute vesicular cavities are not infrequently present, sometimes as negative cubes, and these may contain saline solutions or carbon dioxide or gaseous hydrocarbons.

  • The hydrocarbons are separated from the "Stupp" by means of alcohol, the soluble portion on distillation giving first phenanthrene and then a mixture of pyrene and fluoranthene.

  • In either case the two hydrocarbons are finally separated by fractional crystallization of their picrates, which are then decomposed by ammonia.

  • Gattermann, Ann., 1888, 244, p. 30), melts at 50° C. and boils at 61-62° C. In the presence of anhydrous aluminium chloride it reacts with aromatic hydrocarbons to form the amides of aromatic acids.

  • His most important contribution to organic chemistry was a series of researches, begun in 1835, on the haloid and other derivatives of unsaturated hydrocarbons.

  • Considerable interest is attached to the remarkable series of hydrocarbons obtained by Gomberg (Ber., 1900, 33, p. 3150, et seq.) by acting on triphenylmethane chloride (from triphenylmethane carbinol and phosphorus pentachloride, or from carbon tetrachloride and benzene in the presence of aluminium chloride) and its homologues with zinc, silver or mercury.

  • With aromatic hydrocarbons in the presence of anhydrous aluminium chloride, in the cold, there is a large evolution of hydrochloric acid gas, and an aldehyde is formed; at 100° C., on the other hand, anthracene derivatives are produced.

  • Metallic products represent about three-fourths of the total, but the feature of recent years has been the rising importance of hydrocarbons and gases, and of structural materials, and indeed of non-metallic products generally.

  • In these latter cases the reaction may proceed in different directions; thus, with the aromatic hydrocarbons, chlorine in the cold or in the presence of a carrier substitutes in the benzene nucleus, but in the presence of sunlight or on warming, substitution takes place in the side chain.

  • Molten copper absorbs carbon monoxide, hydrogen and sulphur dioxide; it also appears to decompose hydrocarbons (methane, ethane), absorbing the hydrogen and the carbon separating out.

  • It also yields crystalline compounds with many aromatic hydrocarbons and bases.

  • As the colour is usually expelled, or much altered, by heat, it is believed to be due to an organic pigment, and the presence of hydrocarbons has been detected in many specimens by G.

  • THYMOL, C10H,40 or C 6 H 3 (OH) (CH 3) (C 3 H 7) [1: 3: 6 ], a methylisopropylphenol isomeric with carvacrol, is an aromatic substance found with the hydrocarbons cymene, C, 0 H, 4j and thymene, Collis, in oil of thyme (from Thymus vulgaris) and in other essential oils, e.g.

  • Pfliiger suggests that such compounds arose when the surface of the earth was incandescent, and that in the long process of cooling, compounds of cyanogen and hydrocarbons passed into living protoplasm by such processes of transformation and polymerization as are familiar in the chemical groups in question, and by the acquisition of water and oxygen.

  • von Helmholtz independently raised and discussed the possibility of such an origin of terrestrial life, laying stress on the presence of hydrocarbons in meteoric stones and on the indications of their presence revealed by the spectra of the tails of comets.

  • It can be obtained also, although in a somewhat impure condition, by the direct action of bromine on various saturated hydrocarbons (e.g.

  • They differ from the organic ammonium hydroxides in their behaviour when heated, yielding phosphine oxides and paraffin hydrocarbons: R4P OH=R3PO+RH.

  • Three isomeric hydrocarbons of this formula exist; they occur in the light oil fraction of the coal: tar distillate, but they cannot be separated by fractional distillation owing to the closeness of their boiling points.

  • POLYMETHYLENES, in chemistry, cyclic compounds, the simplest members of which are saturated hydrocarbons of general formula C 7, H 2nj where n may be r to 9, and known as tri-, tetra-, penta-, hexa-, and hepta-methylene, &c., or cyclo- propane, -butane, -pentane, -hexane, -heptane, &c.: - CH 21 CH 2 CH 2 CH2.CH2 CH2 CH2 CH2?C1H,, I I H ?

  • Baeyer, ibid., 1870, 155, p. 266), benzene giving methylpentamethylene; by passing the vapour of benzene hydrocarbons over finely divided nickel at 180-250° C.

  • Unsaturated hydrocarbons of the series may be prepared from the corresponding alcohols by the elimination of a molecule of water, using either the xanthogenic ester method of L.

  • Blanc, Comptes rendus, 1903, 136, p. 1676; 137, p. 60); and by the addition of the elements of water to the unsaturated cyclic hydrocarbons on boiling with dilute acids.

  • Blanc (Comptes rendus, 1903, 136, p. 1460), prepared hydrocarbons of the cyclo-pentane series from cyclo- hexane compounds by the exhaustive methylation process of A.

  • Stobbe, Ann., 1901, 314, p. III; 315, p. 219 seq.; 1903, 326, p. 347 Cyclo-hexane Group. Hydrocarbons.

  • Of artificial productions the most fruitful and important is provided by the destructive or dry distillation of many organic substances; familiar examples are the distillation of coal, which yields ordinary lighting gas, composed of gaseous hydrocarbons, and also coal tar, which, on subsequent fractional distillations, yields many liquid and solid hydrocarbons, all of high industrial value.

  • From the chemical point of view the hydrocarbons are of fundamental importance, and, on account of their great number, and still greater number of derivatives, they are studied as a separate branch of the science, namely, organic chemistry.

  • Bituminous coal, however, may be looked upon as containing carbon and also simple hydrocarbons, such as some of the higher members of the paraffin series, and likewise organic bodies containing carbon, hydrogen, nitrogen, oxygen and sulphur.

  • If bituminous coal is distilled at a low tempera- Destruc- ture, the tar is found to contain considerable quantities of tive dis- light paraffin oils; and there is no doubt that paraffin tillation hydrocarbons are present in the original coal.

  • Ethane, when heated to this degree, splits up into ethylene and hydrogen, whilst ethylene decomposes to methane and acetylene, and the acetylene at once polymerizes to benzene, styrolene, retene, &c. A portion also condenses, and at the same time loses some hydrogen, becoming naphthalene; and the compounds so formed by interactions amongst themselves build up the remainder of the hydrocarbons present in the coal tar, whilst the organic substances containing oxygen in the coal break down, and cause the formation of the phenols in the tar.

  • There is very little doubt that the general course of the decompositions follows these iines; but any such simple explanation of the actions taking place is rendered impossible by the fact that, instead of the breaking-down of the hydrocarbons being completed in the coal, and only secondary reactions taking place in the retort, in practice the hydrocarbons to a great extent leave the coal as the vapours of condensible hydrocarbons, and the breaking down of these to such simple gaseous compounds as ethylene is proceeding in the retort at the same time as the breaking up of the ethylene already formed into acetylene and methane, and the polymerization of the former into higher compounds.

  • Moreover, these secondary products cannot be successfully reduced, by further heating, to simpler hydrocarbons of any high illuminating value, and such bodies as naphthalene and anthracene have so great a stability that, when once formed, they resist any efforts again to decompose them by heat, short of the temperature which breaks them up into methane, carbon and hydrogen.

  • From this it will be seen that, with the increase of temperature, the hydrocarbons - the olefines and marsh gas series - gradually break up, depositing carbon in the crown of the retort, and liberating hydrogen, the percentage of which steadily increases with the rise of temperature.

  • The retort carbon products* formed as a dense deposit on the crown of the retort by the action of the high temperature on the hydrocarbons is, however, carbon in a very pure form, and, on account of its density, is largely used for electrical purposes.

  • The following analysis gives a fair idea of the composition of an average sample of gas made from coal, purified but without enrichment: Ioo 00 These constituents may be divided into - (a) light-yielding hydrocarbons, (b) combustible diluents and (c) impurities.

  • The hydrocarbons, upon which the luminosity of the flame entirely depends, are divided in the analysis into two groups, saturated and unsaturated, according to their behaviour with a solution of bromine in potassium bromide, which has the power of absorbing those termed "unsaturated," but does not affect in diffused daylight the gaseous members of the "saturated" series of hydrocarbons.

  • The chief unsaturated hydrocarbons present in coal gas are: ethylene, C2H4, butylene, C 4 H 8, acetylene, C 2 H 2, benzene, C 6 H 61 and naphthalene,C 10 H 8, and the saturated hydrocarbons consist chieflyof methane, CH 4, and ethane, C2H6.

  • The light-giving power of coal gas is undoubtedly entirely due to the hydrocarbons.

  • But here again another mistaken idea arose, owing to a faulty method of estimating the benzene, and there is no doubt that methane is one of the most important of the hydrocarbons present, when the gas is burnt in such a way as to evolve from it the proper illuminating power, whilst the benzene vapour, small as the quantity is, comes next in importance and the ethylene last.

  • It is the combined action of the hydrocarbons which gives the effect, not any one of them acting alone.

  • The cause of the failure of Murdoch's original vertical retort was undoubtedly that it was completely filled with coal during charging, with the result that the gas liberated from the lower portions of the retort had to pass through a deep bed of red-hot coke, which, by over-baking the gas, destroyed the illuminating hydrocarbons.

  • The solubility of naphthalene by various oils has led some engineers to put in naphthalene washers, in which gas is brought into contact with a heavy tar oil or certain fractions distilled from it, the latter being previously mixed with some volatile hydrocarbon to replace in the gas those illuminating vapours which the oil dissolves out; and by fractional distillation of the washing oil the naphthalene and volatile hydrocarbons are afterwards recovered.

  • A partly successful attempt to make use of certain portions of the liquid products of distillation of coal before condensation by the second method was the Dinsmore process, in which the coal gas and vapours which, if allowed to cool, would form tar, were made to pass through a heated chamber, and a certain proportion of otherwise condensible hydrocarbons was thus converted into permanent gases.

  • The final solution of the question of enrichment of gas by hydrocarbons derived from tar may be arrived at by a process which prevents the formation of part of the tar during the carbonization of the coal, or by the process devised by C. B.

  • decompose the liquid hydrocarbon in the presence of the diluents which are to mingle with it and act as its carrier, since, if this were done, a higher temperature could be employed and more of the heavier portions of the oil converted into gas, without at the same time breaking down the gaseous hydrocarbons too much.

  • In carburetting poor coal gas with hydrocarbons from mineral oil it must be borne in mind that, as coal is undergoing distillation, a rich gas is given off in the earlier stages, but towards the end of the operation the gas is very poor in illuminants, the methane disappearing with the other hydrocarbons, and the increase in hydrogen being very marked.

  • The carburetting of low-power gas by impregnating it with the vapours of volatile hydrocarbons.

  • Mixing the coal gas with water gas, which has been highly carburetted by passing it with the vapours of various hydrocarbons through superheaters in order to give permanency to the hydrocarbon gases.

  • The Mond gas in the dry state contains 15% carbon dioxide, io °,o monoxide, 23% hydrogen, 3% hydrocarbons, 49% nitrogen.

  • TERPENES, in organic chemistry, the generic name of a group of hydrocarbons of the general formula (C 5 H 8) n, and the more important oxygen derivatives, mainly alcohols, aldehydes and ketones, derived from them.

  • Certain of these oils consist very largely of hydrocarbons; for example, those of turpentine, citron, thyme, orange, pine-needle, goldenrod (from Solidago canadensis) and cypress, while others contain as their chief constituents various alcoholic and ketonic substances.

  • Chemically, oil of turpentine is a more or less complex mixture of hydrocarbons generically named terpenes.

  • ALCOHOLS, in organic chemistry, a class of compounds which may be considered as derived from hydrocarbons by the replacement of one or more hydrogen atoms by hydroxyl groups.

  • In 1855 Adolph Wurtz had shown that when sodium acted upon alkyl iodides, the alkyl residues combined to form more complex hydrocarbons; Fittig developed this method by showing that a mixture of an aromatic and alkyl haloid, under similar treatment, yielded homologues of benzene.

  • They also investigated certain hydrocarbons occurring in the high boiling point fraction of the coal tar distillate and solved the constitution of phenanthrene.

  • At the same time hydrocarbons are formed (see Petroleum).

  • 2315) for obtaining oil from crushed seeds, or from refuse cake, by the solvent action of volatile hydrocarbons from "petroleum, earth oils, asphaltum oil, coal oil or shale oil, such hydrocarbons being required to be volatile under 212° F."

  • Since that time the development of the petroleum industry in all parts of the world and the large quantities of low boiling-point hydrocarbons - naphtha - obtained from the petroleum fields, and also the improvements in the apparatus employed, have raised this system of extraction to the rank of a competing practical method of oil production.

  • This first step has led to the synthetical production of the most characteristic substances of essential oils in the laboratory, and the synthetical manufacture of essential oils bade fair to rival in importance the production of tar colours from the hydrocarbons obtained on distilling coal.

  • There is an oil industry adage that exploration for hydrocarbons always loses money, while production of hydrocarbons always makes money.

  • alicyclic hydrocarbons ).

  • aliphatic hydrocarbons.

  • Components of cooked meat that have been suggested to cause this include heterocyclic amines, polycyclic aromatic hydrocarbons, nitrogenous residues and iron.

  • aqueous ethanol, all the hydrocarbons were found to move unimpeded through the columns.

  • aromatic hydrocarbons is set at 20 parts per billion.

  • At present these taxes are applied to: hydrocarbons, alcohol and derivatives, wine and fermented beverages, beer, tobacco... ).

  • Know how to distinguish alkenes (as unsaturated hydrocarbons) from alkanes (as saturated hydrocarbons) using addition reactions with aqueous bromine.

  • Know that the products from the incomplete combustion of hydrocarbons include carbon monoxide.

  • chlorinated hydrocarbons.

  • For example, methyl chloroform is one of the many chlorinated hydrocarbons.

  • combustion of hydrocarbons include carbon monoxide.

  • It consists of high molecular weight hydrocarbons and minor amounts of sulfur and nitrogen compounds.

  • They protect the environment by using oxygen to convert poisonous carbon monoxide and hydrocarbons into harmless carbon dioxide and water.

  • At 50% aqueous ethanol, all the hydrocarbons were found to move unimpeded through the columns.

  • halogenated hydrocarbons (HCFCs ).

  • With the ban on CFCs came a promise to phase out other ' greenhouse gases ', halogenated hydrocarbons (HCFCs ).

  • In the past 7 years, nearly a third of all fatalities in the surface engineering industry have been from exposure to chlorinated hydrocarbons.

  • Alkanes are saturated hydrocarbons; they only contain single bonds.

  • There will be a new Daughter Directive on polycyclic aromatic hydrocarbons.

  • For example, the maximum volume concentration of aromatic hydrocarbons is set at 20 parts per billion.

  • High levels of cancers in fish have been associated with polyaromatic hydrocarbons (PAHs ).

  • Our solvent based paints use two solvents, often in combination: - citrus oils, - aliphatic hydrocarbons.

  • The use of biodiesel results in a substantial reduction of unburned hydrocarbons.

  • Burning also releases soot, nitrogen oxides and non-methane hydrocarbons among other harmful compounds.

  • They deal with carbon monoxide and unburnt hydrocarbons which react with oxygen to produce carbon dioxide and water.

  • In addition, sediment size analysis and chemical analysis for major metals and total petroleum hydrocarbons were required.

  • Potential triggers to develop PCT are alcohol excess, pregnancy, use of estrogen, exposure to poly aromatic hydrocarbons and cigarette smoking.

  • Apart from the most trivial cases (for example, burning hydrocarbons ), never use a molecular formula.

  • Organic deposits forms thick layers on the bottom, eventually metamorphosed by anaerobic bacteria and then pressure to yield hydrocarbons.

  • monocyclic hydrocarbons having one endocyclic double or one triple bond are called cycloalkenes and cycloalkynes, respectively.

  • These chlorinated hydrocarbons work mainly by blocking nerve impulses necessary for normal bodily functions.

  • Smog forming emissions are generally 30-50% lower including nitric oxides and hydrocarbons emissions.

  • Emissions dangerous to health include nitrogen oxides, carbon monoxide, hydrocarbons, lead and particulates.

  • nitrogen oxides produced by cars reacts with hydrocarbons in sunlight.

  • oxidation of natural hydrocarbons.

  • petroleum hydrocarbons were required.

  • polycyclic aromatic hydrocarbons are molecules built up of benzene rings which resemble fragments of single layers of graphite.

  • polynuclear aromatic hydrocarbons (PAHs) could also be detected, derived from anthropogenic combustion sources.

  • The pore fluid may be brine, which is electrically conductive, or hydrocarbons which are electrically resistive.

  • saturated hydrocarbons and know their properties.

  • sulfur oxides, and hydrocarbons.

  • volatile hydrocarbons (excluding methane) set by ISBT at 20 ppmV.

  • To this attitude he offered uncompromising opposition, and by the synthetical production of numerous hydrocarbons, natural fats, sugars and other bodies he proved that organic compounds can be formed by ordinary methods of chemical manipulation and obey the same laws as inorganic substances, thus exhibiting the "creative character in virtue of which chemistry actually realizes the abstract conceptions of its theories and classifications - a prerogative so far possessed neither by the natural nor by the historical sciences."

  • It readily condenses with aromatic hydrocarbons in the presence of sulphuric acid.

  • In order to obtain the phenol from this distillate, it is treated with caustic soda, which dissolves the phenol and its homologues tegether with a certain quantity of naphthalene and other hydrocarbons.

  • The solution is diluted with water, and the hydrocarbons are thereby precipitated and separated.

  • This heat of formation, like that of most hydrocarbons, is comparatively small: the heat of formation of saturated hydrocarbons is always positive, but the heat of formation of unsaturated hydrocarbons is frequently negative.

  • Since the heat of combustion of a hydrocarbon is equal to the heat of combustion of the carbon and hydrogen it contains minus its heat of formation, those hydrocarbons with positive heat of formation generate less heat on burning than the elements from which they were formed, whilst those with a negative heat of formation generate more.

  • Petra, rock, and oleum, oil), a term which, in its widest sense, embraces the whole of the hydrocarbons, gaseous, liquid and solid, occurring in nature (see Bitumen).

  • The calorific power of Baku oil appears to be highest, while this oil is poorest in solid hydrocarbons, of which the American petroleums contain moderate quantities, and the Upper Burma oils the largest amount.

  • The principal elements are found in various combinations, the hydrocarbons of the Pennsylvania oils being mainly paraffins (q.v.), while those of Caucasian petroleum belong for the most part to the naphthenes, isomeric with the olefines (q.v.).

  • Certain crude oils have also been found to contain camphenes, naphthalene and other aromatic hydrocarbons.

  • The " cracking " process, whereby a considerable quantity of the oil which is intermediate between kerosene and lubricating oil is converted into hydrocarbons of lower specific gravity and boiling-point suitable for illuminating purposes, is one of great scientific and technical interest.

  • It is generally understood that the products of fractional distillation, even in the laboratory, are not identical with the hydrocarbons present in the crude oil, but are in part produced by the action of heat upon them.

  • They found that the paraffin was thus converted, with the evolution of but little gas, into hydrocarbons which were liquid at ordinary temperatures.

  • In an experiment on 3500 grams of paraffin produced from shale (melting point 44'5° C.) they obtained nearly 4 litres of liquid hydrocarbons, which they subjected to fractional distillation, and on examining the fraction distilling below loo° C., they found it to consist mainly of olefines.

  • The result of this treatment is that the comparatively heavy oils undergo dissociation, as shown by the experiments of Thorpe and Young, into specifically lighter hydrocarbons of lower boiling points, and the yield of kerosene from ordinary crude petroleum may thus be greatly increased.

  • Under such conditions, distillation takes place at higher temperatures than the normal boiling-points of the constituent hydrocarbons of the oil, and a partial cracking results.

  • In the American petroleum refineries it is found that sufficient cracking can be produced by slow distillation in stills of which the upper part is sufficiently cool to allow of the condensation of the vapours of the less volatile hydrocarbons, the condensed liquid thus falling back into the heated body of oil.

  • The rationale of this treatment is not fully understood, but the action appears to consist in the separation or decomposition of the aromatic hydrocarbons, fatty and other acids, phenols, tarry bodies, &c., which lower the quality of the oil, the sulphuric acid removing some, while the caustic soda takes out the remainder, and neutralizes the acid which has been left in the oil.

  • In France, the standard is 35° C. (Granier tester, equivalent to 98° F.), and according to their flashpoint, liquid hydrocarbons are divided into two classes (below and above 35° C.), considered differently in regard to quantities storable and other regulations.

  • A consequence of this empirical division was that marsh gas, ethylene and cyanogen were regarded as inorganic, and at a later date many other hydrocarbons of undoubtedly organic nature had to be included in the same division.

  • Taking as types hydrogen, hydrochloric acid, water and ammonia, he postulated that all organic compounds were referable to these four forms: the hydrogen type included hydrocarbons, aldehydes and ketones; the hydrochloric acid type, the chlorides, bromides and iodides; the water type, the alcohols, ethers, monobasic acids, acid anhydrides, and the analogous sulphur compounds; and the ammonia type, the amines, acid-amides, and the analogous phosphorus and arsenic compounds.

  • An apt definition of organic chemistry is that it is "the study of the hydrocarbons and their derivatives."

  • This description, although not absolutely comprehensive, serves as a convenient starting-point for a preliminary classification, since a great number of substances, including the most important, are directly referable to hydrocarbons, being formed by replacing one or more hydrogen atoms by other atoms or groups.

  • Two distinct types of hydrocarbons exist: (1) those consisting of an open chain of carbon atoms - named the " aliphatic series " (i.XEicAap, oil or fat), and (2) those consisting of a closed chain - the " carbocyclic series."

  • Let us now consider hydrocarbons containing 2 atoms of carbon.

  • Hydrocarbons containing any number of double or triple linkages, as well as both double and triple linkages, are possible, and a considerable number of such compounds have been prepared.

  • From n-butane we may derive, by a similar substitution of methyl groups, the two hydrocarbons: (I) CH 3 CH 2 CH 2 CH 2 CH 3, and (2) CH 3.

  • These three hydrocarbons are isomeric, i.e.

  • (methylene) groups and the molecule consists of a single chain; such hydrocarbons are referred to as being normal; (2) has a branch and contains the group; CH (methine) in which the free valencies are attached to carbon atoms; such hydrocarbons are termed secondary or iso-; (3) is characterized by a carbon atom linked directly to four other carbon atoms; such hydrocarbons are known as tertiary.

  • Deferring the detailed discussion of cyclic or ringed hydrocarbons, a correlation of the various types or classes of compounds which may be derived from hydrocarbon nuclei will now be given.

  • It is convenient first to consider the effect of introducing one, two, or three hydroxyl (OH) groups into the - CH 3, > CH 2, and >CH groups, which we have seen to characterize the different types of hydrocarbons.

  • We proceed to consider various simple derivatives of the alcohols, which we may here regard as hydroxy hydrocarbons, R OH, where R is an alkyl radical, either aliphatic or cyclic in nature.

  • Cyclic Hydrocarbons and Nuclei.

  • Having passed in rapid review the various types of compounds derived by substituting for hydrogen various atoms or groups of atoms in hydrocarbons (the separate articles on specific compounds should be consulted for more detailed accounts), we now proceed to consider the closed chain compounds.

  • The general behaviour of the several types of hydrocarbons is certainly in accordance with this conception, and it is a remarkable fact that when benzene is reduced with hydriodic acid, it is converted into a mixture of hexamethylene and methylpentamethylene (cf.

  • By fusing two nuclei we obtain the formula of naphthalene, C 1 oH 8; by fusing three, the hydrocarbons anthracene and phenanthrene, C14H10; by fusing four, chrysene, C18H12, and possibly pyrene, C16H1n; by fusing five, picene, C22 H 14.

  • This and other facts connected with the stability of benzenoid compounds are clearly shown when we consider mixed aliphatic-aromatic hydrocarbons, i.e.

  • Thomsen then investigated heats of combustion of various benzenoid hydrocarbons - benzene, naphthalene, anthracene, phenanthrene, &c. - in the crystallized state.

  • But, at the same time, the constants in the above relation are not identical with those in the corresponding relation empirically deduced from observations on fatty hydrocarbons; and we are therefore led to conclude that a benzene union is considerably more stable than an ethylene union.

  • These isomeric hydrocarbons, of the formula C14H10, are to be regarded as formed by the fusion of three.

  • An ethylenic or double carbon union in the aliphatic hydrocarbons has, apparently, the same effect on the boiling-point as two hydrogen atoms, since the compounds C 0 H 2 „ +2 and CoH2n boil at about the same temperature.

  • The same difference attends the introduction of the methyl group into many classes of compounds, for example, the paraffins, olefines, acetylenes, aromatic hydrocarbons, alcohols, aldehydes, ketones and esters, while a slightly lower value (157.1) is found in the case of the halogen compounds, nitriles, amines, acids, ethers, sulphides and nitro compounds.

  • It contains four independent constants; two of these may be calculated from the heats of combustion of saturated hydrocarbons, and the other two from the combustion of hydrocarbons containing double and triple linkages.

  • A more complex chromophoric group is the triple ethylenic grouping: C > C =, the introduction of which was rendered necessary by the discovery of certain coloured hydrocarbons.

  • As a general rule, hydrocarbons are colourless; the exceptions include the golden yellow acenaphthylene, the red bidiphenylene-ethylene, and the derivatives of fulvene CH: CH >CH 2, which have been discussed by CH: CH J.

  • Hydrocarbons of similar structure have been prepared by Thiele, for example, the orange-yellow tetraphenyl-para-xylylene, which is obtained by boiling the bromide C6H4[CBr(C6H5)2]2 with benzene and molecular silver.

  • When solid caoutchouc is strongly heated it breaks down, without change in its ultimate composition, into a number of simpler liquid hydrocarbons of the terpene class (dipentene, di-isoprene, isoprene, &c.), of which one, isoprene (C5H8), is of simpler structure than oil of turpentine (C 10 H 16), from which it can also be obtained by the action of an intense heat.

  • At higher temperatures the viscous liquid suffers decomposition with the formation of various liquid hydrocarbons, principally members of the terpene series.

  • Schultz, Ann., 1879, 196, p. 35); or the two hydrocarbons may be separated by carbon bisulphide, in which anthracene is insoluble.

  • Secondary reactions take place at the same time, yielding more particularly hydrocarbons of the paraffin series.

  • The nitro compounds of the lower members of the paraffin series cannot be prepared by the direct action of nitric acid on the hydrocarbons themselves, but, in the case of some of the higher members of the series direct nitration is possible (M.

  • Berthelot, and shown to be very fruitful in forming hydrocarbons.

  • It is convenient to distinguish between aliphatic and aromatic acids; the first named being derived from open-chain hydrocarbons, the second from ringed hydrocarbon nuclei.

  • Dibasic acids of the paraffin series of hydrocarbons have the general formula C n H 2 (000H) 2 "; malonic and succinic acids are important members.

  • Other reactions which introduce carboxyl groups into aromatic groups are: the action of carbonyl chloride on aromatic hydrocarbons in the presence of aluminium chloride, acid-chlorides being formed which are readily decomposed by water to give the acid; the action of urea chloride Cl�CO�NH 2, cyanuric acid (CONH) 3, nascent cyanic acid, or carbanile on hydrocarbons in the presence of aluminium chloride, acid-amides being obtained which are readily decomposed to give the acid.

  • An important oxidation synthesis of aromatic acids is from hydrocarbons with aliphatic side chains; thus toluene, or methylbenzene, yields benzoic acid, the xylenes, or dimethyl-benzene, yield methyl-benzoic acids and phthalic acids.

  • ALCOHOL, in commerce, the name generally given to "spirits of wine"; in systematic organic chemistry it has a wider meaning, being the generic name of a class of compounds (hydroxy hydrocarbons) of which ordinary alcohol (specifically ethyl alcohol) is a typical member (see Alcohols).

  • It dissolves most organic compounds, resins, hydrocarbons, fatty acids and many metallic salts, sometimes forming, in the latter case, crystalline compounds in which the ethyl alcohol plays a role similar to that of water of crystallization.

  • The action is not properly understood; it may be due to the reducing gases (hydrogen, hydrocarbons, &c.) which are invariably present in wood charcoal.

  • Hydrocarbons, such as petroleum, bitumen, paraffin, &c., are also found occasionally in coal, but more generally in the associated sandstones and limestones of the Carboniferous formation.

  • p This term is founded on a misapprehension of the nature of the occurrence, since, although the softening takes place at a low temperature, still it marks the point at which destructive distillation commences, and hydrocarbons both of a solid and gaseous character are formed.

  • Bone has shown that when exposed for some time to the sun's rays it undergoes certain polymerization changes which lead to the deposition of a film of heavy hydrocarbons on the surface of the tube.

  • The earlier papers deal chiefly with the properties and modes of synthesis of cloud chain hydrocarbons and their derivatives.

  • OLEFINE, in organic chemistry, the generic name given to open chain hydrocarbons having only singly and doubly linked pairs of carbon atoms. The word is derived from the French olefiant (from olefier, to make oil), which was the name given to ethylene, the first member of the series, by the Dutch chemists, J.

  • It is further purified by heating in closed vessels, but even then it still contains a certain amount of mineral matter and more or less hydrocarbons.

  • Gas carbon is produced by the destructive distillation of coal in the manufacture of illuminating gas (see GAS: Manufacture), being probably formed by the decomposition of gaseous hydrocarbons.

  • It may be condensed to a liquid, which boils at 8° C. It is readily soluble in benzene, glacial acetic acid, and in many hydrocarbons.

  • The para or true quinones are obtained by the oxidation of hydrocarbons with chromic acid or of various para di-derivatives of benzene with chromic acid mixture, such, for example, as para-aminophenol, para-phenylene diamine, paraa.minoazobenzene, &c. H.

  • It is only very sparingly soluble in water, but dissolves readily in solutions of the alkaline iodides and in alcohol, ether, carbon bisulphide, chloroform, and many liquid hydrocarbons.

  • in the United States) to a portion of the more volatile hydrocarbons distilled from petroleum (see Petroleum).

  • They may be prepared by the oxidation of secondary alcohols; by the addition of the elements of water to hydrocarbons of the acetylene type RC CH; by oxidation of primary alcohols of the type RR' CH CH 2 OH:RR' CH CH 2 OH --> R CO R'+H20+H2C02; by distillation of the calcium salts of the fatty acids, C.H2.02; by heating the sodium salts of these acids CnH2n02 with the corresponding acid anhydride to 190 C. (W.

  • In the first group we may mention the homologous series of hydrocarbons derived from ethylene, given by the general formula C 7, H 2, ,,, and the two compounds methylene-oxide and honey-sugar C6H1206.

  • Considering the hydrocarbons given by the general formula C x H y, the internal linkages of the carbon atoms need at least xi bonds, using up 2(xI) valencies of the 4x to be accounted for, and thus leaving no more than 2(x-11) for binding hydrogen: a compound C 3 H 9 is therefore impossible, and indeed has never been met.

  • that of the alcohols, which only differ from the hydrocarbons by having a group OH, called hydroxyl, instead of H, hydrogen; these compounds, when derived from the above methane series of hydrocarbons, are expressed by the general formula C7,H27,+10H.

  • It is therefore more probably due to metallic oxides than to hydrocarbons.

  • Other authors have sought the origin of the diamond in the action of the hydrated magnesian silicates on hydrocarbons derived from bituminous schists, or in the decomposition of metallic carbides.

  • Adolf Knop suggested that this may have first yielded hydrocarbons by contact with water, and that from these the crystalline diamond has been formed.

  • Minute vesicular cavities are not infrequently present, sometimes as negative cubes, and these may contain saline solutions or carbon dioxide or gaseous hydrocarbons.

  • The hydrocarbons are separated from the "Stupp" by means of alcohol, the soluble portion on distillation giving first phenanthrene and then a mixture of pyrene and fluoranthene.

  • In either case the two hydrocarbons are finally separated by fractional crystallization of their picrates, which are then decomposed by ammonia.

  • Gattermann, Ann., 1888, 244, p. 30), melts at 50° C. and boils at 61-62° C. In the presence of anhydrous aluminium chloride it reacts with aromatic hydrocarbons to form the amides of aromatic acids.

  • His most important contribution to organic chemistry was a series of researches, begun in 1835, on the haloid and other derivatives of unsaturated hydrocarbons.

  • Considerable interest is attached to the remarkable series of hydrocarbons obtained by Gomberg (Ber., 1900, 33, p. 3150, et seq.) by acting on triphenylmethane chloride (from triphenylmethane carbinol and phosphorus pentachloride, or from carbon tetrachloride and benzene in the presence of aluminium chloride) and its homologues with zinc, silver or mercury.

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