1. SATURATED HIDROCARBONS ALKANE

2. Alkane
= paraffin
= saturated hidrocarbons
= hydrocarbons with only single covalent bonds between the carbon atoms

3. Definition
Acyclic branched or unbranched hydrocarbons having the general formula CnH2n+2 , and therefore consisting entirely of hydrogen atoms and saturated carbon atoms.
IUPAC Gold Book

4. Sifat Sukar bereaksi C1 – C4 pada tekanan & suhu normal fase gas
C5 – C17 pada tekanan & suhu normal fase cair
PC18 pada tekanan & suhu normal fase padat
Mudah larut pada pelarut non polar
Berat jenis naik dengan penambahan atom C
Pada alkana rantai lurus  semakin panjang rantai maka titik didih & titik leleh semakin tinggi

5. Carbon 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).

6. Straight-chain alkanes are sometimes indicated by the prefix n- (for normal)

7. Molecular Formula CnH2n+2
Name
Molecular Formula CnH2n+2
Structural Formula
Methane
CH4
Ethane
C2H6
CH3–CH3
Propane
C3H8
CH3–CH2–CH3
Butane
C4H10
CH3–CH2–CH2–CH3
Pentane
C5H12
CH3–CH2–CH2–CH2–CH3
Hexane
C6H14
CH3–CH2–CH2–CH2–CH2–CH3
Heptane
C7H16
CH3–CH2–CH2–CH2–CH2–CH2–CH3
Octane
C8H18
CH3–CH2–CH2–CH2–CH2–CH2–CH2–CH3
Nonane
C9H20
CH3–CH2–CH2–CH2–CH2–CH2–CH2–CH2–CH3
Decane
C10H22
CH3–CH2–CH2–CH2–CH2–CH2–CH2–CH2–CH2–CH3

8. Isomerism
Alkanes 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

10. Practice 1 : Write structural formulas and
condensed structural formulas of :
Pentane C5H12
Hexane C6H14

11. Pentane

12. Hexane

13. Alkyl Number of carbons Molecule name 1 methyl 2 ethyl 3 propyl
4 butyl
5 pentyl/amyl
6 hexyl
7 heptyl
8 octyl
9 nonyl
10 decyl
11 undecyl
12 dodecyl

14. sec-Butyl
Isopropyl
Isobutyl
tert-Butyl

15. IUPAC 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.

16. IUPAC 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.

17. IUPAC 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).

18. IUPAC 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).

19. IUPAC 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

20. Practice 2 :
The following names are incorrect. Tell why the name is wrong and gave the correct name.
3-methylbutane
2-ethylbutane
2-dimethylpentane
3-methyl-5-ethyloctane
3,5,5-triethylhexane

21. 3-methylbutane
CH3 – CH2 – CH – CH3
CH3
2-methylbutane

22. 2-ethylbutane
CH3 – CH2 – CH – CH3
CH2
CH3
3-methylpentane

23. 2-dimethylpentane
CH3
CH3 – CH – CH – CH2 – CH3
2,2-dimethylpentane

24. 3-methyl-5-ethyloctane
CH3 – CH2 – CH – CH2 – CH – CH2 – CH2 – CH3
CH3 CH2
CH3
5-ethyl-3-methyloctane

25. CH3 – CH2 – CH – CH2 – C – CH3 3,5,5-triethylhexane CH3 CH2 CH2
3,5-diethyl-3-methylheptane

26. Reaction of Alkane : Halogenation
Halogenation means substitution of halogens for hydrogen.
RH + X2  RX + HX
X = F, Cl, Br, I
Example :
CH3CH3 + Cl2  CH3CH2Cl + HCl
chloroethane

27. Reaction of Alkane : Dehydrogenation
Dehydrogenation means removal of hydrogen.
CnH2n – 900 oC CnH2n + H2
Example :
CH3CH2CH3  CH3CH=CH2 + H2
propene

28. Reaction of Alkane : Cracking
Cracking means breaking up large molecules to form smaller ones.
Example :
C16H34  C8H18 + C8H16
alkane alkane alkene

29. Reaction of Alkane : Isomerization
Isomerization means rearrangement of molecular structures.
Example :

30. Chlorination Products of Methane (1)
CH4 + Cl2  CH3Cl
CH3Cl + Cl2  CH2Cl2
CH2Cl2 + Cl2  CHCl3
CHCl3 + Cl2  CCl4 + HCl

31. Chlorination Products of Methane (2)
Formula IUPAC name Common name
CH3Cl Chloromethane Methyl chloryde
CH2Cl2 Dichloromethane Methylene chloryde
CHCl3 Trichloromethane Chloroform
CCl4 Tetrachloromethane Carbon tetrachloride

32. Cycloalkane/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: CnH2n
Contoh:

33. Cyclopropane Cyclobutane Cyclopentane Cyclohexane
C3H C4H8 C5H C6H12

34. Sources of Alkanes

35. The two main sources of alkanes are
natural gas and petroleum / crude oil.
Natural gas consists of :
Methane
Other hydrocarbons
Hydrogen
Nitrogen
Carbon monoxide
Carbon dioxide
Hydrogen sulfide (just in some location)

36. Petroleum is formed by the decomposition of plants and animals over million of years.
Carbon
Hydrogen
Nitrogen
Oxygen
Sulfur
Metals
Four different types of hydrocarbon molecules appear in crude oil :
Paraffins
Naphthenes
Aromatics
Asphaltics

37. Fractional Distillation of Crude Oil

39. Crude 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.

41. Octane Rating

42. Octane CH3(CH2)6CH3 Octane has 18 structural isomers :
Octane (n-octane) 0
2-Methylheptane
3-Methylheptane
4-Methylheptane
3-Ethylhexane
2,2-Dimethylhexane
2,3-Dimethylhexane
2,4-Dimethylhexane
2,5-Dimethylhexane
3,3-Dimethylhexane
3,4-Dimethylhexane
2-Methyl-3-ethylpentane
3-Methyl-3-ethylpentane
2,2,3-Trimethylpentane
2,2,4-Trimethylpentane (isooctane) 100
2,3,3-Trimethylpentane
2,3,4-Trimethylpentane
2,2,3,3-Tetramethylbutane

43. The 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.

44. The 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 :
Toluene
Xylene
Methyl tert-butyl ether (MTBE)