Chapter 24 Organic Chemistry

1.  24.1 Classes of Organic compounds
 24.2 Alphatic hydrocarbons
 Alkane
 cycloalkane
 Alkenes
 Alkynes
 Aromatic hydrocarbon
 Chemistry of functional groups
 Alcohol , ethers , aldhyde and ketones ,carboxylic
acid , esters
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2.  The chemistry of carbon compounds.
 Carbon has the ability to form long chains and ring
structure.
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3.  Alkanes have the general formula CnH2n+2 where n = 1,2,3,…
 only single covalent bonds (C-C), sp3 hybridization
 saturated hydrocarbons because they contain the maximum
number of hydrogen atoms that can bond with the number of
carbon atoms in the molecule.
 Boiling point increase with increase molecular size because of
the increasing dispersion.
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4. Dr.Laila Al-Harbi
24-2

5.  IUPAC International Union of Pure and Applied Chemistry.
 each name consist of 3 parts
 prefix
indicates position (1,3,…etc.) , number (di,tri, tetra …etc.) and
type of branches (alkyl or substituent groups table 24-3)
parent
 indicates the length of the longest carbon chain or ring
 suffix
 indicates the type of hydrocarbon
 ane, ene, yne
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6. Dr.Laila Al-Harbi
24-2

7. Dr.Laila Al-Harbi
1 2 3 4 5
2-methylpentane
CH3 CH CH2 CH2 CH3
CH3
1 2 3 4 5
4-methylpentane
CH3 CH2 CH2 CH CH3
CH3
CH3 CH CH CH2 CH2 CH3
CH3
1 2 3 4 5 6
CH3
2,3-dimethylhexane
CH3 CH C CH2 CH2 CH3
CH3
1 2 3 4 5 6
CH3
3,3-dimethylhexane
Use prefixes di-, tri-, tetra-,
when there is more
than one alkyl branch
of the same kind.

8. Dr.Laila Al-Harbi
CH3 CH CH2 CH2 CH CH3
CH3Br
2-bromo-5-methylhexane
CH3 CH CH CH3
Br
1 2 3 4
NO2
2-bromo-3-nitrobutane
CH2 CH2 CH CH3
Br
1 2 3 4
NO2
3-bromo-1-nitrobutane
The substituent group are
listed alphabetically

9. Dr.Laila Al-Harbi

10. Dr.Laila Al-Harbi

11. What is the IUPAC name of the following compound?
1 2 3 4 5 6 7 8
CH3 CH CH2 CH CH2 CH2 CH3
C2H5
CH2
CH3
4-ethyl-2-methyloctane
What is the structure of 2-propyl-4-methylhexane?
1 2 3 4 5 6
CH3 CH CH2 CH CH2 CH3
CH3C3H7
Dr.Laila Al-Harbi

12.  Molecular formulae: A molecular formula simply counts the numbers of
each sort of atom present in the molecule, but tells you nothing about the
way they are joined together.
 Example:
 the molecular formula of butane is C4H10, and the molecular formula of
ethanol is C2H6O.
 Structural formulae: A structural formula shows how the various atoms
are bonded.
 Example:
 ethanoic acid would be shown in a fully displayed form and asimplified
form as:
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13. Dr.Laila Al-Harbi

14. Dr.Laila Al-Harbi
How many structural isomers does pentane, C5H12, have?
C C C C C
H H H H H
H
HHHHH
H
C C C C
H CH3 H H
H
HHHH
H
C C C
H CH3 H
H
HH
H
CH3
2,2-dimethylpropane
n-pentane
2-methylbutane

15. Reactions of Alkanes
CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (l) ∆H0 = -890.4 kJ
1-Combustion ( exothermic)
2- Halogenations
CH4 (g) + Cl2 (g) CH3Cl (g) + HCl (g)light
2C2H6 (g) + 7O2 (g) → 4CO2 (g) + 6H2O (l) ∆H0 = -3119 kJ
If an excess of chlorine gas is present, the reaction can proceed
further:
CH3Cl(g) + Cl2(g) → CH2Cl2(l) + HCl(g)
methylene chloride
CH2Cl2(l) + Cl2(g) → CHCl3(l) + HCl(g)
chloroform
CHCl3(l) + Cl2(g) → CCl4(l) + HCl(g)
carbon tetrachloride
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Alkane not very reactive

16. Cycloalkanes
Alkanes whose carbon atoms are joined in rings are called cycloalkanes.
The general formula is Cn H2n where n = 3,4,… ( cycloalkane)
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17. Alkenes
Alkenes have the general formula CnH2n where n = 2,3,… (sp2)
contain at least one carbon-carbon double bond ( also called olefins)
CH2
CH CH2 CH3 CH3 CH CH CH3
cis-dichloroethylene trans-dichloroethylene
C C
Cl Cl
H H
C C
Cl H
H Cl
Geometric isomers of alkenes
2-butene1-butene
Cracking
C2H6 (g) CH2 = CH2 (g) + H2 (g)
Pt
catalyst
Dr.Laila Al-Harbi

18. Dr.Laila Al-Harbi
Which of the following compounds has geometrical isomer ?
C C
H Cl
H H
C C
H Cl
H Cl
C C
NO2 Cl
H H
C C
NO2 Cl
H Cl
C C
Cl Cl
H H
NO ,Geometrical isomer NO ,Geometrical isomer
NO ,Geometrical isomer
yes ,it has geometrical isomer
yes ,it has geometrical isomer

19. Alkenes Reactions
Addition Reactions
CH2 = CH2 (g) + HBr (g) CH3- CH2Br (g)
CH2 = CH2 (g) + Br2 (g) → CH2B - CH2Br (g)
Symmetrical alkene
unsymmetrical alkene
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20. Alkynes
Alkynes have the general formula CnH2n-2 where n = 2,3,4,…
• contain at least one carbon-carbon triple bond (sp)
1-butyne
2-butyne
CH C CH2 CH3
CH3 C C CH3
Production of acetylene
CaC2 (s) + 2H2O (l) → C2H2 (g) + Ca(OH)2 (aq)
Alkynes Reactions
1-Hydrogenation
CH ≡ CH (g) + H2 (g)→ CH2 ≡CH2 (g)
2-Addition Reactions
CH ≡ CH (g) + HBr (g) → CH2 ≡ CHBr (g)
CH ≡CHCH3 (g) + HBr (g) → CH2=CHCH3 (g)
Br
-
3-oxidation
2C2H2 (g) + O2 (g)→ 4CO2 +2H2O
4-decomposition
C2H2 (g) → 2C(s) + H2 (g)
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21. C
C
C
CC
C
H
H
H
H
H
H
C
C
C
CC
C
H
H
H
H
H
H
 Aromatic compound contain one or more benzene ring
Aromatic Compound Nomenclature
If one H atom has been replaced by another atom or a group of atom
>>the name of the atom or group then benzene
CH2CH3 Cl
chlorobenzene
NH2 NO2
nitrobenzeneethylbenzene aminobenzene
Dr.Laila Al-Harbi

22. Aromatic Compound Nomenclature
1
2
3
4
5
6
Br
Br
1,2-dibromobenzene
Br
Br
1,3-dibromobenzene
If more than one substituent is present >>we must indicate the location of the second
group relative to first then benzene
Br
Br
o-dibromobenzene m-dibromobenzene
1,4-dibromobenzene
p-dibromobenzene
NO2
Br
m-bromonitrobenzene
CH3-CH-CH3
2-phenylpropane
Dr.Laila Al-Harbi

23. Aromatic Compound Reactions
H
H
H
H
H
H
Br
H
H
H
H
H
+ HBr+ Br2
FeBr3
catalyst
H
H
H
H
H
H
CH2CH3
H
H
H
H
H
+ HCl+ CH3CH2Cl
AlCl3
catalyst
1- Substitution reaction
2- hydrogenation
Pt
catalyst
Dr.Laila Al-Harbi

24.  Polymers are large molecules made up of repeating units
called Monomers
 Proteins are polymers of amino acids ; they play a key role in
nearly all biological process. Proteins high molar mass;
ranging from about 5000 g.
 The basic structural unit of protein is amino acids
 Amino acid is a compound that contains at least one amino
group(-NH2) and at least one carboxyl group(-COOH)
C CH
H
NH2
O
OH
Dr.Laila Al-Harbi

25. Structure – an amino acid possesses both a carboxyl and an amino
group. The most common in the biological amino acids are the a-amino
acids. The amino acid exists as a dipolar ion , possessing both a positive
charge and a negative charge.
NH2
O
R
OH
NH3+
O
R
O
Dipolar ion
20 different amino acids are the building blocks of all proteins in the
human body
The amino group of one molecule condenses with the acid group of
another to gives Protein through peptide bonds
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26. Compounds Functional gp. Comments
1-alcohol R-OH
2-Ethers R-O-R’ R=R’ , R≠ R’
R (Hydrocarbon , aromatic )
3-ketone R=R’ , R≠ R’
R (Hydrocarbon , aromatic )
4-aldhyde
5-carboxilic acid
6- ester R=R’ , R≠ R’
R (Hydrocarbon , aromatic )
7- amine R3N R2NH , RNH2
8-Amino acid
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Term used to refer to parts of organic molecules where reactions tend to occur.
R - C - H
O=
R - C – R’
O
=
R - C - OH
O
=
R - C – OR’
O
=
R-CH - C - OH
O
=
NH2
-

27. Dr.Laila Al-Harbi
CH3 O CH2 CH3
CH3 CH2 NH2
CH3 CH2 C
O
H
CH3 C CH2 CH3
O
H C
O
OH
CH3 CH2CH2 OH
CH2 C
NH2
H
C
O
OH
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(Ether)
(Amine)
(Aldehyde)
(Ketone)
(Carboxylic Acid)
(Alcohol)
(Amino Acid)