2Alkane= paraffin= saturated hidrocarbons= hydrocarbons with only single covalent bonds between the carbon atoms
3DefinitionAcyclic branched or unbranched hydrocarbons having the general formula CnH2n+2 , and therefore consisting entirely of hydrogen atoms and saturated carbon atoms.IUPAC Gold Book
4Sifat Sukar bereaksi C1 – C4 pada tekanan & suhu normal fase gas C5 – C17 pada tekanan & suhu normal fase cairPC18 pada tekanan & suhu normal fase padatMudah larut pada pelarut non polarBerat jenis naik dengan penambahan atom CPada alkana rantai lurus semakin panjang rantai maka titik didih & titik leleh semakin tinggi
5Carbon Bonding in Alkane Each carbon atom must have 4 bonds (either C–H or C–C bonds),and each hydrogen atom must be joined to a carbon atom (H–C bonds).
6Straight-chain alkanes are sometimes indicated by the prefix n- (for normal)
7Molecular Formula CnH2n+2 NameMolecular Formula CnH2n+2Structural FormulaMethaneCH4EthaneC2H6CH3–CH3PropaneC3H8CH3–CH2–CH3ButaneC4H10CH3–CH2–CH2–CH3PentaneC5H12CH3–CH2–CH2–CH2–CH3HexaneC6H14CH3–CH2–CH2–CH2–CH2–CH3HeptaneC7H16CH3–CH2–CH2–CH2–CH2–CH2–CH3OctaneC8H18CH3–CH2–CH2–CH2–CH2–CH2–CH2–CH3NonaneC9H20CH3–CH2–CH2–CH2–CH2–CH2–CH2–CH2–CH3DecaneC10H22CH3–CH2–CH2–CH2–CH2–CH2–CH2–CH2–CH2–CH3
8IsomerismAlkanes with more than three carbon atoms can be arranged in a multiple number of ways, forming different structural isomers.Isomers are compounds that have the same molecular formula but different structural formulas.College Chemistry_ch.21.8_p.529
15IUPAC Nomenclature : Basic Principles (1) Select the longest continuous chain of carbon atoms as the parent compound, and consider all alkyl groups attached to it as side chains that have replaced hydrogen atoms of the parents hydrocarbon.The name of the alkane consists of the name of the parent compound prefixed by the names of the side-chain alkyl groups attached to it.
16IUPAC Nomenclature : Basic Principles (2) Number the carbon atoms in the parent carbon chain starting from the end closest to the first carbon atom that has an alkyl or other group substitued for a hydrogen atom.
17IUPAC Nomenclature : Basic Principles (3) Name each side-chain alkyl group and designate its position on the parent carbon chain by a number (for example, 2-methyl means a methyl group attached to carbon number 2).
18IUPAC Nomenclature : Basic Principles (4) When the same alkyl-group side chain occurs more than once, indicate this by a prefix (di-, tri-, tetra-, and si forth) written in front of the alkyl-group name (for example, dimethyl indicates two methyl groups).The numbers indicating the positions of these alkyl groups are separated by a comma and followed by a hypen and are placed in front of the name (for example, 2,3-dimethyl).
19IUPAC Nomenclature : Basic Principles (5) When several different alkyl groups are attached to the parent compound, list them in alphabetical order; for example, ethyl before methyl in 3-ethyl-4-methyloctane.College Chemistry_ch.21.9_p.533
20Practice 2 :The following names are incorrect. Tell why the name is wrong and gave the correct name.3-methylbutane2-ethylbutane2-dimethylpentane3-methyl-5-ethyloctane3,5,5-triethylhexane
31Chlorination Products of Methane (2) Formula IUPAC name Common nameCH3Cl Chloromethane Methyl chlorydeCH2Cl2 Dichloromethane Methylene chlorydeCHCl3 Trichloromethane ChloroformCCl4 Tetrachloromethane Carbon tetrachloride
32Cycloalkane/cycloparaffin/naphtane Cycloalkanes are types of alkanes which have one or more rings of carbon atoms in the chemical structure of their molecules struktur alisiklik.Rumus: CnH2nContoh:
35The two main sources of alkanes are natural gas and petroleum / crude oil.Natural gas consists of :MethaneOther hydrocarbonsHydrogenNitrogenCarbon monoxideCarbon dioxideHydrogen sulfide (just in some location)
36Petroleum is formed by the decomposition of plants and animals over million of years. CarbonHydrogenNitrogenOxygenSulfurMetalsFour different types of hydrocarbon molecules appear in crude oil :ParaffinsNaphthenesAromaticsAsphaltics
39Crude oil is separated into fractions by fractional distillation Crude oil is separated into fractions by fractional distillation. The fractions at the top of the fractional column have lower boiling points than the fractions at the bottom. The heavy bottom fractions are often cracked into lighter, more useful products. All of the fractions are processed further in other refining units.
43The octane rating was developed by chemist Russel Marker at the Ethyl Corporation at The selection of n-heptane as the zero point of the scale was due to the availability of very high purity n-heptane, not mixed with other isomers of heptane or octane, distilled from the resin of the Jeffrey Pine. Other sources of heptane produced from crude oil contain a mixture of different isomers with greatly differing ratings, which would not give a precise zero point.Higher octane ratings correlate to higher activation energies. Activation energy is the amount of energy necessary to start a chemical reaction. Since higher octane fuels have higher activation energies, it is less likely that a given compression will cause detonation.
44The alternative method to boost octane rating and minimize engine knocking is too add small amounts of an additive to the fuel. One such additive commonly used in gasoline was tetraethyllead, (C2H5)4Pb.The function of tetraethyllead is to prevent the premature explosions that constitute knocking.Use of tetraetthyllead additives poses a serious enviromental hazard. Lead becomes pollutant in air, water, and sovent.Current additives in anleaded gasoline :TolueneXyleneMethyl tert-butyl ether (MTBE)