Al2o3 on measured catalytic rates and selectivity to establish the mechanistic cycles and catalytic site requirements for the corresponding reactions. Number the substituents and write the name listing the substituents in alphabetical order. Organic chemistry science at yorkdale with jessica. This document is highly rated by class 11 students and has been viewed 19934 times.
Petroleum and natural gas are the major sources of aliphatic hydrocarbon while coal is an important source of aromatic hydrocarbons. There are only two reactions that alkanes will undergo, both of which are freeradical. The letter in brackets, x, designates the type of reaction mechanism. General methods of preparation of alkanes wurtz reaction. Part i library of synthetic reactions 1 note that this is a partial list of reactions 1 graphics are obtained mostly from stony brook university che 327 powerpoint slides and organic chemistry, 10th edition by solomons. Department of chemistry, university of virginia, charlottesville, va 22904, usa department of chemistry and princeton institute for the science and technology of. Vicinal dihalides are made from alkenes and bromine. Reactions of alkyl halides the alkyl halides are chemically versatile. The reactions lead to functionalization at secondary ch bonds over tertiary ch bonds and even occur at primary ch bonds. These reactions include free radical halogenations of alkanes and free radical additions to alkenes.
Unsaturated hydrocarbons have double or triple bonds and are quite reactive. Most chemical reactions require a functional group. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carboncarbon bonds are single. The conversion of an alkene to an alkyne, therefore, involves two steps. Reactions of alkanes reactions of alkanes combustion monohalogenation ring. Selective monooxidation of light alkanes using chloride. Unitunitunit national council of educational research.
Reactions of alkanes the alkanes and cycloalkanes, with the exception of cyclopropane, are probably the least chemically reactive class of organic compounds. Coppercatalyzed oxidative dehydrogenative carboxylation of. Other types of reaction have been substitution and elimination. Our modern society is based to a large degree on the chemicals we discuss in this chapter. This reaction is known as wurtz reaction and is used for the preparation of higher alkanes containing even number of carbon atoms. By studying the typical mechanisms involved when reagents add to double bonds, you will be able to predict the outcomes of alkene addition reactions that you have not seen before. Alkanes are generally less reactive than alkenes and alkynes because they lack the more reactive double and triple bonds. You must complete the tests with bromine and potassium permanganate parts c and d above before doing an unknown. In addition to carbon dioxide, water and heat a variety of products are possible. B halogenation halogenation a substitution reaction.
The reaction is highly exothermic, and can lead to an explosion. Alkanes when we combine the two high bond enthalpy and being nonpolar this makes alkanes quite unreactive alkanes dont react with acidsbases or oxidizing agents this is a useful trait and alkanes are used as lubricating agents and the backbone of polymers but when the do react. Alkanes formula, definition, structure, properties, videos. Learn the important physical and chemical properties of the alkanes. Alkanes are stable compounds and are generally unreactive. In dry ethereal solution, on treating alkyl halides with sodium metal, production of alkanes is higher. Reactions of alkanes 8 alkanes are generally considered unreactive as they have no functional groups present.
Alkanes are comprised of a series of compounds that contain carbon and hydrogen atoms with single covalent bonds. The reactions of primary and secondary alcohols with hcl require the presence of a catalyst, zncl 2. Download in free pdf hydrocarbons are composed of carbon and hydrogen. This will be followed by a brief survey of the occurrence and uses of hydrocarbons, with special reference to the petroleum industry. In organic chemistry, an alkane, or paraffin a historical name that also has other meanings, is an acyclic saturated hydrocarbon. Alkanes when we combine the two high bond enthalpy and being nonpolar this makes alkanes quite unreactive alkanes dont react with acidsbases or oxidizing agents this is a useful trait and alkanes are used as lubricating agents and the backbone of polymers but when the do react look out. Detailed chapter notes alkanes, class 11, chemistry. The first 12 nalkanes are listed in the handout essential nomenclature. Boiling points, melting points, and densities generally increase with the size of the alkane. Alkyl iodides are often prepared by the reaction of alkyl chlorides bromides with nai in dry acetone.
Organic reactions summary alkenes, alkynes and variations for. Since alkanes are the most fundamental types of organic compounds, their structural features a basic carbon chain, or skeleton provide the basis for the nomenclature of all organic compounds. A brief look at cracking alkanes in the oil industry. Selective monooxidation of light alkanes using chloride and iodate george c. Complex organic compounds can perform a number of useful biological functions vitamins, carbohydrates, lipids, proteins, enzymes, atp, dna, rna are all organic compounds which are studied in biochemistry. Here is a comprehensive and a beautiful pdf file of the alkene addition reactions. In wourtz reaction a solution of alkyl halide in ether on heating with sodium gives alkane. Reactions of alkenes and alkynes alkenes and alkynes are generally more reactive than alkanes due to the electron density available in their pi bonds. Here is a comprehensive and a beautiful pdf file of the. Feb 21, 2020 detailed chapter notes alkanes, class 11, chemistry edurev notes is made by best teachers of class 11. In particular, these molecules can participate in a variety of addition reactions and can be used in polymer formation. Cliffsnotes study guides are written by real teachers and professors, so no matter what youre studying, cliffsnotes can ease your homework headaches and help you score high on exams. The names of alkanes containing up to twelve carbon atoms per chain are as follows.
For phenols, follow benzene nomenclature and use phenol as the parent name. Reactions of alkanes ib combustion of alkanes alkanes are unreactive as a family because of the strong cc and ch bonds as well as them being nonpolar compounds. Ch08 reacns of alkenes landscape page 1 reactions of alkenes since bonds are stronger than bonds, double bonds tend to react to convert the double bond into bonds this is an addition reaction. Reactions of alkenes reactions of alkenes electrophilic catalytic carbene oxidative addition halohydrogenation acid catalyzed hydration oxymercurationdemercuration hydroborationoxidation hydrogenation cyclopropanation halogenation halohydrin formation epoxidation antihydroxylation synhydroxylation oxidative cleavage via. To me it appears like a primeval tropical forest full of the most remarkable things, a dreadful endless jungle into. Since alkanes are the major components of petroleum and natural gas, they often serve as a commercial starting point for the preparation of many other classes of organic molecules. There are only two reactions that alkanes will undergo, both of which are free radical. Alkanes are less dense than water and swim on top of water 2. General methods of preparation of alkanes is the topic which has a potential of fetching a question in iit jee and jee mainadvanced examination very frequently. This type of transformation is related to the pummerer rearrangement.
Nucleophilic substitution nucleophilic substitution reactions of haloalkanes sn1 versus sn2 mechanisms haloalkane structure and reactivity stereochemistry of sn reactions reaction rates of sn reactions other nucleophiles leaving groups nucleophilicity and reaction solvent. Alkanes can be prepared from alkyl halides except fluorides through reduction with zinc and dilute hydrochloric acid. However, all saturated hydrocarbons are attacked by oxygen at ele vated temperatures and, if oxygen is in excess, complete combustion to carbon dioxide and. Introduction of a halogen into a molecule chlorination, bromination general reaction. Steadystate chemical reactions of alkanol dehydration and alkane hydroisomerization were employed as probe reactions to evaluate the effects of structure and composition of zeolites and gamma alumina. Synthesis of chloroalkanes reaction of alkanes with bromine chlorine in uv light. Substitution reactions of alkanes reaction of alkanes with bromine chlorine in uv light in the presence of uv light alkanes react with chlorine to form a mixture of products with the halogens substituting hydrogen atoms.
In the presence of uv light alkanes react with chlorine to form a mixture of products with the halogens substituting hydrogen atoms. Organic chemistry university of california riverside. Reaction of alkanes with bromine chlorine in uv light in the presence of uv light alkanes react with chlorine to form a mixture of products with the halogens substituting hydrogen atoms. The hydrogen atoms of the alkane are progressively replaced by halogen atoms. Reactions of alkenes and alkynes introduction to chemistry. To me it appears like a primeval tropical forest full of the most remarkable things, a dreadful endless jungle into which one does not dare enter, for there seems to be no way out. Organic reactions summary alkenes, alkynes and variations. The order of increasing s n2 reaction rates is c reactions. Such eliminationseliminations areare alsoalso calledcalled. Most reactions of alkenes involve addition of atoms or groups across the double bond, with one atom or group adding to each end. Free radicals are the reactive species that participate in the reaction, which usually leads to a mixture of products. For alkenes, alkynes and aromatic hydrocarbons, spring models can be constructed. To work out the best way to distinguish alkanes from alkenes. Smaller, linear alkanes generally oxidize more readily than larger, more branched molecules.
The most important application of alkanes is in oxidation reactions. However, anyone who has used a match to light a gas burner, or dropped a match onto charcoal coated with lighter fluid, should recognize that alkanes burst into. An knowledge organiser on alevel organic chemistry, the hydrocarbons alkanes and alkenes including. Preparation of alkanes from unsaturated hydrocarbons. An introduction to the alkanes including cycloalkanes and their physical properties. Consequently the bonds in alkanes are not susceptible to attack by most common chemical reagents. Preparation of alkanes from carboxylic acids, alkyl halides. This is because the cc bond and the ch bond are relatively strong overall. Alkanesandalkenesworksheet how can we distinguish between alkanes and alkenes. With tertiary alcohols, the reaction is conducted by simply shaking with concentrated hcl at room temperature. In the absence of a spark or a highintensity light source, alkanes are generally inert to chemical reactions. Determine which class of hydrocarbons alkane, alkene, or alkyne that your unknown belongs to by reacting it with.
Lecture handouts organic chemistry i chemistry mit. Physical properties of alkanes alkanes are nonpolar only dispersion forces act between molecules. We report a set of rare coppercatalyzed reactions of alkanes with simple amides, sulfonamides, and imides i. Since alkanes are the major components of petroleum and. Nacl or nabr thus formed is precipitated in dry acetone. Unsaturated hydrocarbons alkenes and alkynes react with h 2 in the presence of finely divided catalysts such as platinum, palladium or nickel to form alkanes. Alkane names are based on the number of carbon atoms in the longest continuous chain in the compound. The halogen atom may leave with its bonding pair of electrons to give a halide ion which is stable a halide is called a good leaving group. Learn the iupac system for naming alkanes and cycloalkanes. Despite their relative inertness, alkanes undergo several important reactions that are discussed in the following section. In general, alkanes do not react with many reagents. The physical properties of alkenes are similar to those of the alkanes. Alkanes are organic compounds that consist entirely of singlebonded carbon and hydrogen atoms and lack any other functional groups.
The addition reactions of alkenes are the big start of going deep into organic reaction mechanisms in the upcoming topics such as alkynes, radical reactions, aromatic compounds and most of the others. Named reactions of haloalkanes and haloarenes 1finkelstein reaction this reaction used for the preparation of iodoalkenes from the corresponding chloroalkanes or bromo alkanes. Probe reactions of alcohols and alkanes for understanding. The combustion of alkanes, including incomplete combustion. This is chemical properties of alkanes, section 12.
The equation below shows the isomerisation of heptane into 2methylhexane. This is because the cc bond and the ch bond are relatively strong. Alkanes are organic compounds that consist of singlebonded carbon and hydrogen atoms. However, they do participate in reactions with oxygen combustion and halogens. As a result alkanes do not react with electron rich species. However, ignoring financial considerations, alkanes can be prepared from the following compounds. Double elimination from dibromoalkanes to form alkynes and terminal acetylides used in many additional reactions sn2 with rbr, co addition to aldehyses and ketones, and reaction with epoxides br br h n r r na br h h n r r h n r r na na 2. Here we look at the features of alkanes that make them generally unreactive, before looking at some of. These reactions are employed to illustrate how we can predict and use energy changesparticularly ah, the heat evolved or absorbed by a reacting system, which often can be estimated from bond ener gies. The important fuels like petrol, kerosene, coal gas, cng, lpg etc. The alkanes and cycloalkanes, with the exception of cyclopropane, are probably the least chemically reactive class of organic compounds. The reaction between alkanes and chlorine or bromine. An alkyl halide on wurtz reaction leads to the formation of symmetrical alkane having an even number of carbon atoms.
Alkanes 2 organic chemistry nowadays almost drives me mad. Alkanes have a number of industrial applications beyond fuels, including uses in cosmetics and plastics. Alkanes can be burned in the presence of oxygen to produce carbon dioxide, water, and energy. Jul 30, 2014 6th in a series of 15 films covering the sl organic topic in the ib diploma chemistry course.
The most important reaction that alkanes undergo is combustion. Organocuprates gilman reagents couple with alkyl halides to provide alkanes. Identify each as an alkane, an alkene, or an alkyne. This section deals with wurtz reaction,frankland reaction. Alkanes are quite inert substances with highly stable nature. Alkanes are rarely prepared from other types of compounds because of economic reasons. For making models of alkanes, you can use toothpicks for bonds and plasticine balls for atoms. Good yields of ri may be obtained by heating alcohols. It facilitates the forward reaction according to le chateliers principle. Constant boiling with hbr 48% is used for preparing alkyl bromide. Sep 03, 2018 synthesis of chloroalkanes reaction of alkanes with bromine chlorine in uv light in the presence of uv light alkanes react with chlorine to form a mixture of products with the halogens substituting hydrogen atoms.