Misplaced Pages

#400599

67-603: Butane ( / ˈ b juː t eɪ n / ) is an alkane with the formula C 4 H 10 . Butane exists as two isomers, n -butane with connectivity CH 3 CH 2 CH 2 CH 3 and iso-butane with the formula (CH 3 ) 3 CH . Both isomers are highly flammable, colorless, easily liquefied gases that quickly vaporize at room temperature and pressure. Butanes are a trace components of natural gases (NG gases). The other hydrocarbons in NG include propane , ethane , and especially methane , which are more abundant. Liquefied petroleum gas

134-534: A 4-carbon molecule and only attaches oxygen and removes water; the 4-C-base body of the molecule remains intact. Overall, the newer method is therefore more material efficient . Parallels exist with the production of phthalic anhydride : While older methods use naphthalene , modern methods use o -xylene as feedstock. The chemistry of maleic anhydride is very rich, reflecting its ready availability and bifunctional reactivity. It hydrolyzes, producing maleic acid , cis -HOOC–CH=CH–COOH. With alcohols,

201-482: A C–H bond and 1.54 × 10  m for a C–C bond. The spatial arrangement of the bonds is similar to that of the four sp orbitals—they are tetrahedrally arranged, with an angle of 109.47° between them. Structural formulae that represent the bonds as being at right angles to one another, while both common and useful, do not accurately depict the geometry. The spatial arrangement of the C-C and C-H bonds are described by

268-445: A branched-chain alkane due to the greater surface area in contact, and thus greater van der Waals forces, between adjacent molecules. For example, compare isobutane (2-methylpropane) and n-butane (butane), which boil at −12 and 0 °C, and 2,2-dimethylbutane and 2,3-dimethylbutane which boil at 50 and 58 °C, respectively. On the other hand, cycloalkanes tend to have higher boiling points than their linear counterparts due to

335-574: A fuel for cooking, barbecues and camping stoves. In the 20th century, the Braun company of Germany made a cordless hair styling device product that used butane as its heat source to produce steam . As fuel, butane is often mixed with small amounts of mercaptans to give the unburned gas an offensive smell easily detected by the human nose. In this way, butane leaks can easily be identified. While hydrogen sulfide and mercaptans are toxic, they are present in levels so low that suffocation and fire hazard by

402-486: A mixture of antimony pentafluoride (SbF 5 ) and fluorosulfonic acid (HSO 3 F), called magic acid , can protonate alkanes. All alkanes react with oxygen in a combustion reaction, although they become increasingly difficult to ignite as the number of carbon atoms increases. The general equation for complete combustion is: In the absence of sufficient oxygen, carbon monoxide or even soot can be formed, as shown below: Maleic anhydride Maleic anhydride

469-708: A negative effect on the demand for lubricating oil additives, giving flat growth prospects for maleic anhydride in this application. A number of smaller applications exist for maleic anhydride. Personal care products consuming maleic anhydride include hair sprays, adhesives and floor polishes. Maleic anhydride is also a precursor to compounds used for water treatment detergents, insecticides and fungicides, pharmaceuticals, and other copolymers. The maleic anhydride group occurs in several natural products, some of which show promising therapeutic or pesticidal activity. Source : Kirk & Othmer Solid State Chemicals, Ltd. started production of solid maleic anhydride pastilles in

536-413: A stream of hot air, and the mixture is passed through a catalyst bed at high temperature. The ratio of air to hydrocarbon is controlled to prevent the mixture from igniting. Vanadium pentoxide and molybdenum trioxide are the catalysts used for the benzene route, whereas vanadium phosphate is used for the butane route: The main competing process entails full combustion of the butane, a conversion that

603-441: A sufficiently long time. Since alkanes have high ionization energies , their electron impact mass spectra show weak currents for their molecular ions. The fragmentation pattern can be difficult to interpret, but in the case of branched chain alkanes, the carbon chain is preferentially cleaved at tertiary or quaternary carbons due to the relative stability of the resulting free radicals . The mass spectra for straight-chain alkanes

670-439: A systematic name. The key steps in the naming of more complicated branched alkanes are as follows: Though technically distinct from the alkanes, this class of hydrocarbons is referred to by some as the "cyclic alkanes." As their description implies, they contain one or more rings. Simple cycloalkanes have a prefix "cyclo-" to distinguish them from alkanes. Cycloalkanes are named as per their acyclic counterparts with respect to

737-443: Is sp -hybridized with 4 sigma bonds (either C–C or C–H ), and each hydrogen atom is joined to one of the carbon atoms (in a C–H bond). The longest series of linked carbon atoms in a molecule is known as its carbon skeleton or carbon backbone. The number of carbon atoms may be considered as the size of the alkane. One group of the higher alkanes are waxes , solids at standard ambient temperature and pressure (SATP), for which

SECTION 10

#1732873392401

804-424: Is a dangerous material in accordance with RID/ADR. Solid maleic anhydride pellets are transported by trucks. Packaging is generally in 25 kg polyethylene bags. This compound poses relatively low-risk environmental hazards, an important feature for some applications. In humans , exposure to maleic anhydride may cause irritation to the respiratory tract , eyes , exposed mucosa , and skin . Maleic anhydride

871-486: Is a general term and often does not distinguish between pure compounds and mixtures of isomers , i.e., compounds of the same chemical formula , e.g., pentane and isopentane . The following trivial names are retained in the IUPAC system: Some non-IUPAC trivial names are occasionally used: All alkanes are colorless. Alkanes with the lowest molecular weights are gases, those of intermediate molecular weight are liquids, and

938-453: Is a mixture of propane and some butanes. The name butane comes from the root but- (from butyric acid , named after the Greek word for butter ) and the suffix -ane . The first synthesis of butane was accidentally achieved by British chemist Edward Francland in 1849 from ethyl iodide and zinc , but he had not realized that the ethyl radical dimerized and misidentified the substance. It

1005-502: Is also a ligand for low-valent metal complexes, examples being Pt(PPh 3 ) 2 (MA) and Fe(CO) 4 (MA). On account of its cycle of 4 π electrons in an array of 5 atoms with p orbitals, maleic anhydride was long thought to exhibit antiaromaticity . However, a thermochemical study concluded that only 8 kJ/mol of destabilization energy can be ascribed to this effect, making it weakly antiaromatic at best. Maleic anhydride has many applications. Around 50% of world maleic anhydride output

1072-413: Is also a skin and respiratory sensitizer. Maleic anhydride is a low hazard profile chemical. Maleic anhydride rapidly hydrolyzes to form maleic acid in the presence of water and hence environmental exposures to maleic anhydride itself are unlikely. Maleic acid is biodegradable under aerobic conditions in sewage sludge as well as in soil and water . Food starch for use in night markets sold from

1139-728: Is an acyclic saturated hydrocarbon . In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carbon–carbon bonds are single . Alkanes have the general chemical formula C n H 2 n +2 . The alkanes range in complexity from the simplest case of methane ( CH 4 ), where n  = 1 (sometimes called the parent molecule), to arbitrarily large and complex molecules, like pentacontane ( C 50 H 102 ) or 6-ethyl-2-methyl-5-(1-methylethyl) octane, an isomer of tetradecane ( C 14 H 30 ). The International Union of Pure and Applied Chemistry (IUPAC) defines alkanes as "acyclic branched or unbranched hydrocarbons having

1206-435: Is an alkane-based molecular fragment that bears one open valence for bonding. They are generally abbreviated with the symbol for any organyl group , R, although Alk is sometimes used to specifically symbolize an alkyl group (as opposed to an alkenyl group or aryl group). Ordinarily the C-C single bond distance is 1.53 ångströms (1.53 × 10  m). Saturated hydrocarbons can be linear, branched, or cyclic . The third group

1273-448: Is denser than air. When there is sufficient oxygen: When oxygen is limited: By weight, butane contains about 49.5  MJ / kg (13.8  kWh /kg; 22.5 MJ/ lb ; 21,300  Btu /lb) or by liquid volume 29.7 megajoules per liter (8.3 kWh/L; 112 MJ/U.S. gal; 107,000 Btu/U.S. gal). The maximum adiabatic flame temperature of butane with air is 2,243 K (1,970 °C; 3,578 °F). n -Butane

1340-473: Is derived from the electron configuration of carbon , which has four valence electrons . The carbon atoms in alkanes are described as sp hybrids; that is to say that, to a good approximation, the valence electrons are in orbitals directed towards the corners of a tetrahedron which are derived from the combination of the 2s orbital and the three 2p orbitals. Geometrically, the angle between the bonds are cos (− ⁠ 1 / 3 ⁠ ) ≈ 109.47°. This

1407-456: Is exact for the case of methane, while larger alkanes containing a combination of C–H and C–C bonds generally have bonds that are within several degrees of this idealized value. An alkane has only C–H and C–C single bonds. The former result from the overlap of an sp orbital of carbon with the 1s orbital of a hydrogen; the latter by the overlap of two sp orbitals on adjacent carbon atoms. The bond lengths amount to 1.09 × 10  m for

SECTION 20

#1732873392401

1474-553: Is illustrated by that for dodecane : the fragment resulting from the loss of a single methyl group ( M  − 15) is absent, fragments are more intense than the molecular ion and are spaced by intervals of 14 mass units, corresponding to loss of CH 2 groups. Alkanes are only weakly reactive with most chemical compounds. They only reacts with the strongest of electrophilic reagents by virtue of their strong C–H bonds (~100 kcal/mol) and C–C bonds (~90 kcal/mol). They are also relatively unreactive toward free radicals. This inertness

1541-416: Is lower than operating pressures for halomethanes such as Freon-12 (R-12). Hence, R-12 systems, such as those in automotive air conditioning systems, when converted to pure butane, will function poorly. Instead, a mixture of isobutane and propane is used to give cooling system performance comparable to R-12. Butane is also used as lighter fuel for common lighters or butane torches , and is sold bottled as

1608-490: Is not necessarily the most common). However, the chain of carbon atoms may also be branched at one or more points. The number of possible isomers increases rapidly with the number of carbon atoms. For example, for acyclic alkanes: Branched alkanes can be chiral . For example, 3-methylhexane and its higher homologues are chiral due to their stereogenic center at carbon atom number 3. The above list only includes differences of connectivity, not stereochemistry. In addition to

1675-468: Is produced by methanogenic bacteria and some long-chain alkanes function as pheromones in certain animal species or as protective waxes in plants and fungi. Nevertheless, most alkanes do not have much biological activity . They can be viewed as molecular trees upon which can be hung the more active/reactive functional groups of biological molecules. The alkanes have two main commercial sources: petroleum (crude oil) and natural gas . An alkyl group

1742-485: Is produced by vapor-phase oxidation of n -butane . The overall process converts the methyl groups to carboxylate and dehydrogenates the backbone. The selectivity of the process reflects the robustness of maleic anhydride, with its conjugated double-bond system. Traditionally maleic anhydride was produced by the oxidation of benzene or other aromatic compounds . As of 2006, only a few smaller plants continue to use benzene. In both cases, benzene and butane are fed into

1809-421: Is relatively high, a property that is called lipophilicity . Alkanes are, for example, miscible in all proportions among themselves. The density of the alkanes usually increases with the number of carbon atoms but remains less than that of water. Hence, alkanes form the upper layer in an alkane–water mixture. The molecular structure of the alkanes directly affects their physical and chemical characteristics. It

1876-428: Is sometimes called cycloalkanes . Very complicated structures are possible by combining linear, branch, cyclic alkanes. Alkanes with more than three carbon atoms can be arranged in various ways, forming structural isomers . The simplest isomer of an alkane is the one in which the carbon atoms are arranged in a single chain with no branches. This isomer is sometimes called the n -isomer ( n for "normal", although it

1943-401: Is the feedstock for DuPont 's catalytic process for the preparation of maleic anhydride : n -Butane, like all hydrocarbons , undergoes free radical chlorination providing both 1-chloro- and 2-chlorobutanes, as well as more highly chlorinated derivatives. The relative rates of the chlorinations are partially explained by the differing bond dissociation energies : 425 and 411 kJ / mol for

2010-571: Is the main component used to manipulate the Reid vapor pressure (RVP). Since winter fuels require much higher vapor pressure for engines to start, refineries raise the RVP by blending more butane into the fuel. n-Butane has a relatively high research octane number (RON) and motor octane number (MON), which are 93 and 92 respectively. When blended with propane and other hydrocarbons, the mixture may be referred to commercially as liquefied petroleum gas (LPG). It

2077-619: Is the most commonly abused volatile substance in the UK, and was the cause of 52% of solvent related deaths in 2000. By spraying butane directly into the throat, the jet of fluid can cool rapidly to −20 °C (−4 °F) by expansion, causing prolonged laryngospasm . "Sudden sniffer's death" syndrome, first described by Bass in 1970, is the most common single cause of solvent related deaths, resulting in 55% of known fatal cases. Alkane In organic chemistry , an alkane , or paraffin (a historical trivial name that also has other meanings ),

Butane - Misplaced Pages Continue

2144-703: Is the source of the term paraffins (with the meaning here of "lacking affinity"). In crude oil the alkane molecules have remained chemically unchanged for millions of years. The acid dissociation constant (p K a ) values of all alkanes are estimated to range from 50 to 70, depending on the extrapolation method, hence they are extremely weak acids that are practically inert to bases (see: carbon acids ). They are also extremely weak bases, undergoing no observable protonation in pure sulfuric acid ( H 0 ~ −12), although superacids that are at least millions of times stronger have been known to protonate them to give hypercoordinate alkanium ions (see: methanium ion ). Thus,

2211-424: Is twice as exothermic as the partial oxidation. The traditional method using benzene became uneconomical due to the high and still rising benzene prices and by complying with the regulations of benzene emissions . In addition, in the production of maleic anhydride (4 C-atoms) a third of the original carbon atoms is lost as carbon dioxide when using benzene (6 carbon atoms). The modern catalytic processes start from

2278-441: Is used as a petrol component, as a feedstock for the production of base petrochemicals in steam cracking , as fuel for cigarette lighters and as a propellant in aerosol sprays such as deodorants . Pure forms of butane, especially isobutane, are used as refrigerants and have largely replaced the ozone-layer-depleting halomethanes in refrigerators, freezers, and air conditioning systems. The operating pressure for butane

2345-453: Is used as a solvent in the industrial extraction of cannabis oils. Inhalation of butane can cause euphoria , drowsiness , unconsciousness , asphyxia , cardiac arrhythmia , fluctuations in blood pressure and temporary memory loss, when abused directly from a highly pressurized container, and can result in death from asphyxiation and ventricular fibrillation . Butane enters the blood supply, and within seconds, leads to intoxication. Butane

2412-563: Is used in the manufacture of unsaturated polyester resins (UPR). Chopped glass fibers are added to UPR to produce fiberglass reinforced plastics that are used in a wide range of applications such as pleasure boats , bathroom fixtures, automobiles, tanks and pipes. Maleic anhydride is hydrogenated to 1,4-butanediol (BDO), used in the production of thermoplastic polyurethanes , elastane/Spandex fibers, polybutylene terephthalate (PBT) resins and many other products. Diels-Alder reaction of maleic anhydride and butadiene and isoprene gives

2479-452: The Michael reaction with active methylene or methine compounds. These intermediates were used for the same Krebs cycle intermediates aconitic and isocitric acids. Maleic anhydride dimerizes in a photochemical reaction to form cyclobutane tetracarboxylic dianhydride (CBTA). This compound is used in the production of polyimides and as an alignment film for liquid crystal displays . It

2546-579: The "looser"-organized solid packing structure requires less energy to break apart. For a visualization of the crystal structures see. The melting points of branched-chain alkanes can be either higher or lower than those of the corresponding straight-chain alkanes, again depending on the ability of the alkane in question to pack well in the solid phase. Alkanes do not conduct electricity in any way, nor are they substantially polarized by an electric field . For this reason, they do not form hydrogen bonds and are insoluble in polar solvents such as water. Since

2613-470: The C-C stretching mode absorbs between 800 and 1300 cm . The carbon–hydrogen bending modes depend on the nature of the group: methyl groups show bands at 1450 cm and 1375 cm , while methylene groups show bands at 1465 cm and 1450 cm . Carbon chains with more than four carbon atoms show a weak absorption at around 725 cm . The proton resonances of alkanes are usually found at δ H = 0.5–1.5. The carbon-13 resonances depend on

2680-499: The USA in 2014. World Maleic Anhydride Capacity By Region Data in: kilotonnes per annum Source : Kirk & Othmer Liquid maleic anhydride is available in road tankers and/or tank-containers which are made of stainless steel, which are insulated and provided with heating systems to maintain the temperature of 65-75 °C. Tank cars must be approved for the transport of molten maleic anhydride. Liquid/molten maleic anhydride

2747-480: The alkane isomers, the chain of carbon atoms may form one or more rings. Such compounds are called cycloalkanes , and are also excluded from the above list because changing the number of rings changes the molecular formula . For example, cyclobutane and methylcyclopropane are isomers of each other (C 4 H 8 ), but are not isomers of butane (C 4 H 10 ). Branched alkanes are more thermodynamically stable than their linear (or less branched) isomers. For example,

Butane - Misplaced Pages Continue

2814-554: The basic numerical term. Hence, pentane , C 5 H 12 ; hexane , C 6 H 14 ; heptane , C 7 H 16 ; octane , C 8 H 18 ; etc. The numeral prefix is generally Greek; however, alkanes with a carbon atom count ending in nine, for example nonane , use the Latin prefix non- . Simple branched alkanes often have a common name using a prefix to distinguish them from linear alkanes, for example n -pentane , isopentane , and neopentane . IUPAC naming conventions can be used to produce

2881-438: The better put together solid structures will require more energy to break apart. For alkanes, this can be seen from the graph above (i.e., the blue line). The odd-numbered alkanes have a lower trend in melting points than even-numbered alkanes. This is because even-numbered alkanes pack well in the solid phase, forming a well-organized structure which requires more energy to break apart. The odd-numbered alkanes pack less well and so

2948-405: The boiling point of alkanes is primarily determined by weight, it should not be a surprise that the boiling point has an almost linear relationship with the size ( molecular weight ) of the molecule. As a rule of thumb, the boiling point rises 20–30 °C for each carbon added to the chain; this rule applies to other homologous series. A straight-chain alkane will have a boiling point higher than

3015-427: The bond angle may differ from the optimal value (109.5°) to accommodate bulky groups. Such distortions introduce a tension in the molecule, known as steric hindrance or strain. Strain substantially increases reactivity. Spectroscopic signatures for alkanes are obtainable by the major characterization techniques. The C-H stretching mode gives a strong absorptions between 2850 and 2960  cm and weaker bands for

3082-515: The butane becomes a concern far before toxicity . Most commercially available butane also contains some contaminant oil, which can be removed by filtration. If not removed, it will otherwise leave a deposit at the point of ignition and may eventually block the uniform flow of gas. The butane used as a solvent for fragrance extraction does not contain these contaminants. Butane gas can cause gas explosions in poorly ventilated areas if leaks go unnoticed and are ignited by spark or flame. Purified butane

3149-489: The density of liquid butane is 625.5±0.7 kg/m (for pressures up to 2 MPa and temperature −13±0.2 °C). Rotation about the central C−C bond produces two different conformations ( trans and gauche ) for n -butane. When oxygen is plentiful, butane undergoes complete combustion to form carbon dioxide and water vapor ; when oxygen is limited, due to incomplete combustion , carbon ( soot ) or carbon monoxide may be formed instead of carbon dioxide. Butane

3216-412: The general formula C n H 2 n +2 , and therefore consisting entirely of hydrogen atoms and saturated carbon atoms". However, some sources use the term to denote any saturated hydrocarbon, including those that are either monocyclic (i.e. the cycloalkanes ) or polycyclic , despite them having a distinct general formula (e.g. cycloalkanes are C n H 2 n ). In an alkane, each carbon atom

3283-589: The half-ester is generated, e.g., cis -HOOC–CH=CH–COOCH 3 . Maleic anhydride is a classic substrate for Diels-Alder reactions . It was used for work in 1928, on the reaction between maleic anhydride and 1,3-butadiene, for which Otto Paul Hermann Diels and Kurt Alder were awarded the Nobel Prize in 1950. It is through this reaction that maleic anhydride is converted to many pesticides and pharmaceuticals. Their 1928 patent also provided many other examples of reactions involving maleic anhydride, such as

3350-442: The heaviest are waxy solids. Alkanes experience intermolecular van der Waals forces . The cumulative effects of these intermolecular forces give rise to greater boiling points of alkanes. Two factors influence the strength of the van der Waals forces: Under standard conditions , from CH 4 to C 4 H 10 alkanes are gaseous; from C 5 H 12 to C 17 H 36 they are liquids; and after C 18 H 38 they are solids. As

3417-473: The highly branched 2,2,3,3-tetramethylbutane is about 1.9 kcal/mol more stable than its linear isomer, n -octane. The IUPAC nomenclature (systematic way of naming compounds) for alkanes is based on identifying hydrocarbon chains. Unbranched, saturated hydrocarbon chains are named systematically with a Greek numerical prefix denoting the number of carbons and the suffix "-ane". In 1866, August Wilhelm von Hofmann suggested systematizing nomenclature by using

SECTION 50

#1732873392401

3484-539: The hydrogen bonds between individual water molecules are aligned away from an alkane molecule, the coexistence of an alkane and water leads to an increase in molecular order (a reduction in entropy ). As there is no significant bonding between water molecules and alkane molecules, the second law of thermodynamics suggests that this reduction in entropy should be minimized by minimizing the contact between alkane and water: Alkanes are said to be hydrophobic as they are insoluble in water. Their solubility in nonpolar solvents

3551-497: The locked conformations of the molecules, which give a plane of intermolecular contact. 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 a more rigid and fixed structure than liquids. This rigid structure requires energy to break down. Thus

3618-512: The mixture was patented in 1913. Butane is one of the most produced industrial chemicals in the 21st century, with around 80-90 billion lbs (40 million US tons, 36 million metric tons ) produced by the United States every year. The density of butane is highly dependent on temperature and pressure in the reservoir. For example, the density of liquid butane is 571.8±1 kg/m (for pressures up to 2 MPa and temperature 27±0.2 °C), while

3685-440: The name "quartane", and the modern name was introduced to English from German around 1874. Butane did not have much practical use until the 1910s, when W. Snelling identified butane and propane as components in gasoline. He found that if they were cooled, they could be stored in a volume-reduced liquified state in pressurized containers. In 1911, Snelling's liquified petroleum gas was publicly available, and his process for producing

3752-433: The number of carbon atoms in the carbon backbone is greater than about 17. With their repeated – CH 2 units, the alkanes constitute a homologous series of organic compounds in which the members differ in molecular mass by multiples of 14.03  u (the total mass of each such methylene-bridge unit, which comprises a single carbon atom of mass 12.01 u and two hydrogen atoms of mass ~1.01 u each). Methane

3819-449: The number of carbon atoms in their backbones, e.g., cyclopentane (C 5 H 10 ) is a cycloalkane with 5 carbon atoms just like pentane (C 5 H 12 ), but they are joined up in a five-membered ring. In a similar manner, propane and cyclopropane , butane and cyclobutane , etc. Substituted cycloalkanes are named similarly to substituted alkanes – the cycloalkane ring is stated, and the substituents are according to their position on

3886-416: The number of hydrogen atoms attached to the carbon: δ C = 8–30 (primary, methyl, –CH 3 ), 15–55 (secondary, methylene, –CH 2 –), 20–60 (tertiary, methyne, C–H) and quaternary. The carbon-13 resonance of quaternary carbon atoms is characteristically weak, due to the lack of nuclear Overhauser effect and the long relaxation time , and can be missed in weak samples, or samples that have not been run for

3953-451: The petroleum industry are linear paraffins or n -paraffins . The first eight members of the series (in terms of number of carbon atoms) are named as follows: The first four names were derived from methanol , ether , propionic acid and butyric acid . Alkanes with five or more carbon atoms are named by adding the suffix -ane to the appropriate numerical multiplier prefix with elision of any terminal vowel ( -a or -o ) from

4020-422: The prefix "n-" or " n -"(for "normal") where a non-linear isomer exists. Although this is not strictly necessary and is not part of the IUPAC naming system, the usage is still common in cases where one wishes to emphasize or distinguish between the straight-chain and branched-chain isomers, e.g., " n -butane " rather than simply "butane" to differentiate it from isobutane . Alternative names for this group used in

4087-491: The reaction with cyclopentadiene to form nadic anhydride . Michael reaction of maleic anhydride with active methylene or methine compounds such as malonate or acetoacetate esters in the presence of sodium acetate catalyst. These intermediates were subsequently used for the generation of the Krebs cycle intermediates aconitic and isocitric acids. Likewise at higher temperatures, the half salts, half esters of maleic acid undergo

SECTION 60

#1732873392401

4154-424: The respective tetrahydrophthalic anhydrides which can be hydrogenated to the corresponding hexahydrophthalic anhydrides. These species are used as curing agents in epoxy resins . Another market for maleic anhydride is lubricating oil additives, which are used in gasoline and diesel engine crankcase oils as dispersants and corrosion inhibitors. Changes in lubricant specifications and more efficient engines have had

4221-548: The ring, with the numbering decided by the Cahn–Ingold–Prelog priority rules . The trivial (non- systematic ) name for alkanes is 'paraffins'. Together, alkanes are known as the 'paraffin series'. Trivial names for compounds are usually historical artifacts. They were coined before the development of systematic names, and have been retained due to familiar usage in industry. Cycloalkanes are also called naphthenes. Branched-chain alkanes are called isoparaffins . "Paraffin"

4288-471: The torsion angles of the molecule is known as its conformation . In ethane , the simplest case for studying the conformation of alkanes, there is nearly free rotation about a carbon–carbon single bond. Two limiting conformations are important: eclipsed conformation and staggered conformation . The staggered conformation is 12.6 kJ/mol (3.0 kcal/mol) lower in energy (more stable) than the eclipsed conformation (the least stable). In highly branched alkanes,

4355-421: The two types of C-H bonds. Normal butane can be used for gasoline blending, as a fuel gas, fragrance extraction solvent, either alone or in a mixture with propane , and as a feedstock for the manufacture of ethylene and butadiene , a key ingredient of synthetic rubber . Isobutane is primarily used by refineries to enhance (increase) the octane number of motor gasoline. For gasoline blending, n-butane

4422-433: The whole sequence of vowels a, e, i, o and u to create suffixes -ane, -ene, -ine (or -yne), -one, -une, for the hydrocarbons C n H 2 n +2 , C n H 2 n , C n H 2 n −2 , C n H 2 n −4 , C n H 2 n −6 . In modern nomenclature, the first three specifically name hydrocarbons with single, double and triple bonds; while "-one" now represents a ketone . Straight-chain alkanes are sometimes indicated by

4489-556: Was discovered in crude petroleum in 1864 by Edmund Ronalds , who was the first to describe its properties, which he named "hydride of butyl ", based on the naming for the then-known butyric acid , which had been named and described by the French chemist Michel Eugène Chevreul 40 years earlier. Other names arose in the 1860s: "butyl hydride", "hydride of tetryl" and "tetryl hydride", "diethyl" or "ethyl ethylide" and others. August Wilhelm von Hofmann , in his 1866 systemic nomenclature, proposed

#400599