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General Physical Science
Organic Chemistry
Organic Chemistry
 Scientists had originally thought that organic
compounds contained a “vital force” due to their
natural origin.

This was disproved by Friedrich Wöhler in 1828.
 Wöhler was able to make urea, a carbon compound
in human urine, in the laboratory from a mineral.
 Organic chemistry is the chemistry of carbon
compounds
 Inorganic chemistry is the chemistry of compounds
of all elements other than carbon.
2
Organic Chemistry
The general properties of carbon compounds are:
1. Most carbon compounds are nonelectrolytes.
2. The reaction rates of carbon compounds are
usually slow.
3. Many carbon compounds oxidize slowly in air
but rapidly if heated.
4. Most carbon compounds are unstable at high
temperatures.
3
Bonding in Organic Compounds
 Besides carbon, the most common elements in
organic compounds are hydrogen, oxygen, nitrogen,
sulfur, and the halogens.
 All of the preceding elements are non-metals,
therefore organic compounds have covalent bonding.
S
H2
N2
O2
F2
Halogens
Group 7A
Cl2
I2
Br2
4
Numbers and Types of Bonds
Application of the octet rule indicates that these elements should bond as
shown below:
Element
Total Bonds
C
4
N
3
O
2
H
1
5
Section 14.1
Example
- Identifying Structural Formulas
 Two structural formulas are shown above. Which one
does not represent a real compound?
 In structure (a) each H and halogen has one bond, each C
has four bonds, and each O has two bonds.
 This is a valid structure.
6
Section 14.1
Example - Identifying Structural Formulas
 As we examine (b), we note that each H has one
bond, each C has four bonds, the N has three bonds,
BUT the O has three bonds.
 The O should only have two bonds.
 Therefore (b) is not a valid structure.
7
Section 14.1
Example 2 - Identifying Structural Formulas
H3C
O
O
CH3
C
N
N
C
C
C
N
CH
N
CH3
 The structural formula above appears in a recent
chemistry book. Check the number of bonds to each
atom and determine whether any bonding rules are
violated.
8
Section 14.1
Example 2 - Identifying Structural Formulas
O should have
two bonds, C
should have 4
bonds
Each C
should have 4
bonds
H3C
O
CH3
C
N
N
C
C
C
O
N
CH
N
CH3
This is not a valid
structure for caffeine!
Each N should
have 3 bonds
9
Section 14.1
Hydrocarbons
 Hydrocarbons are the most simple organic
compounds.
 Hydrocarbons contain only carbon (C) and
hydrogen. (H)
 For classification purposes, all other organic
compounds are considered derivatives of
hydrocarbons.
 Hydrocarbons can be divided into aromatic
and aliphatic hydrocarbons.
10
Section 14.2
Classification of Hydrocarbons
Hydrocarbons
Aromatic
Aliphatic
Alkanes
Cycloalkanes
Alkenes
Alkynes
11
Section 14.2
Aromatic Hydrocarbons
 Aromatic hydrocarbons contain one or more
benzene ring.
 Benzene (C6H6) is the most important
aromatic hydrocarbon.
 It is a clear, colorless liquid with a distinct
odor, and is a carcinogen (cancer-causing
agent.)
 Traditional Lewis Structure
12
Section 14.2
Benzene
Structural Formulas and Short-hand Symbols
 The Lewis structure and the Kekulé symbol both indicate that
the carbons in the ring have alternating double and single
bonds.
Benzene
(Kekule symbol)
Benzene
(modern symbol)
13
Section 14.2
Benzene representation
 Benzene representation
showing a flat molecule with six
delocalized electrons forming a
cloud above and below the
plane of the ring.
 Properties of the benzene
molecule and advanced
bonding theory indicate this
structure.
 The six electrons appear to be
shared by all the carbon atoms
in the ring.
14
Section 14.2
When Other Atoms are Substituted for
the H’s in the Benzene Ring
A vast array of other compounds can be produced
CH3
O2 N
NO2
NO2
TNT (2,4,6-trinitrotoluene)
15
Section 14.2
Example - Drawing Benzene Derivatives
 Draw the structural formula for
1,3-dibromobenzene.
 First, Draw a benzene ring.
16
Section 14.2
Example - Drawing Benzene Derivatives
 Second, attach a bromine atom (“bromo”) to
the carbon atom at the ring position you
choose to be number 1.
Br
17
Section 14.2
Example - Drawing Benzene Derivatives
 Third, attach a second (“di”) bromine atom to ring
position 3 (you may number either clockwise or
counterclockwise from carbon 1) and you have the
answer.
 1,3-dibromobenzene
Br
Br
18
Section 14.2
Benzene
Aromatic compounds
naphthalene
anthracene
phenanthrene
C10H8
C14H10
C14H10
chrysene
C18H12
Aliphatic compounds are organic compounds that
do not contain benzene rings.
19
Aliphatic Hydrocarbons
 Aliphatic hydrocarbons are hydrocarbons
having no benzene rings.
 Aliphatic hydrocarbons can be divided into
four major divisions:




Alkanes
Cycloalkanes
Alkenes
Alkynes
20
Section 14.3
Alkanes
 Alkanes are hydrocarbons that contain only single
bonds.
 Alkanes are said to be saturated hydrocarbons






Because their hydrogen content is at a maximum.
Alkane general formula  CnH2n + 2
The names of alkanes all end in “-ane.”
Methane  butane are gases
Pentane  C17H36 are liquids
C18H38 and higher are solids
21
Section 14.3
Structural Formulas
Alkanes or Hydrocarbons
Methane 1 carbon
Ethane
CH4
2 carbons
Propane 3 carbons
Butane
4 carbons
CH3 –CH2 –CH2 -CH3
Pentane 5 carbons
Hexane 6 carbons
Heptane 7 carbons
Octane
9 carbons
22
The First Eight of the Alkane Series
All satisfy the general formula CnH2n + 2
Name
Molecular Formula
Methane
CH4
Ethane
C2H6
Propane
C3H8
Butane
C4H10
Pentane
C5H12
Hexane
C6H14
Heptane
C7H16
Octane
C8H18
23
Section 14.3
Visualization of an Alkane’s Structure
H
H
H–C–C–H
H
H
CH3CH3
Structural formula – a graphical
representation of the way atoms
are connected
Condensed structural formula –
save time/space and are
convenient
Ball-and-Stick models – 3D
models that can be built by
students
24
Section 14.3
Models of Three Alkanes
 Names, Structural Formulas, Condensed Structural Formulas,
and Ball-and-Stick Models
Ethane
H
Full structural
formula:
H–C–C–H
H
Condensed
structural formula:
H
H
CH3CH3
Ball and Stick
Model:
25
Section 14.3
Methane – Tetrahedral Geometry
Ball-and-Stick
& SpaceFilling Models
Carbon’s four
single bonds
form angles
of 109.5o
H
C
H
H
H
26
Section 14.3
Alkanes – Energy Related Products
 Methane = primary component of natural gas
 Propane & Butane = primary component of
bottled gas
 Gasoline = pentane to decane
 Kerosene = alkanes with n = 10 to 16
 Alkanes with n > 16  diesel fuel, fuel oil,
petroleum jelly, paraffin wax, lubricating oil,
and asphalt
27
Section 14.3
Petroleum Products
Fractional distillation
C1 to C4 Gases
20oC
C5 to C9
70oC
C5 to C10
120oC
C10 to C16
170oC
C14 to C20
270oC
C20 to C50
450oC
600oC
Catalytic cracking
Modern cracking uses zeolites as the
catalyst.
C20 to C70
>C70
28
Petroleum Products
42 gallons = 1 barrel
Petroleum
Asphalt
Boiler oil
Other
Jet fuel
1.25 gal
1.3 gal
2.9 gal
4.2 gal
4.2 gal
Diesel fuel
8.4 gal
Gasoline
19.7 gal
29
Alkyl Group
 Alkyl group contains one less hydrogen than
the corresponding alkane.
 In naming this group the “-ane” is dropped
and “-yl” is added.
 For example, methane becomes methyl.
 Ethane becomes ethyl.
30
Section 14.3
Alkyl Group
This group does not exist independently but occurs
bonded to another atom or molecule.
H
H
H–C–H
H–C–
H
H
Methane
Methyl group
CH3
31
Section 14.3
Constitutional Isomers
 Compounds that have the same molecular formula




but different structural formulas
In the case of many alkanes there is more than one
way to arrange the atoms
For example butane and isobutane
Both of these alkanes have the molecular formula of
C4H10
But their structural formula and arrangement is quite
different
32
Section 14.3
Butane
Continuous-Chain or
Straight-Chain Structure
H
H
H
H
H–C–C–C–C–H
H
H
H
C4H10
H
33
Section 14.3
Isobutane (2-methylpropane)
Branched-chain Structure
C4H10
34
Section 14.3
Constitutional Isomers
 Constitutional Isomers may exist whenever it
is possible to construct a different structural
arrangement:


Using the same number and types of atoms
Without violating the octet rule
 In other words, the same atoms may be
connected to one another in different, but
valid, ways.
35
Section 14.3
Number of Possible Isomers of
Alkanes
 Carbon Atoms can bond in many
different ways
Name
Molecular Formula
Number of Isomers
Methane
CH4
1
Ethane
C2H6
1
Propane
C3H8
1
Butane
C4H10
2
Pentane
C5H12
3
Hexane
C6H14
5
Heptane
C7H16
9
Octane
C8H18
18
C15H32
4,347
36
Section 14.3
IUPAC System of Nomenclature
 Compound is named as a derivative of the longest
continuous chain of C atoms.
 Positions & names of the substituents added


If necessary, substituents named alphabetically
More than one of same type substituent – di, tri, tetra
 The C atoms on the main chain are numbered by
counting from the end of the chain nearest the
substituents.

Each substituent must have a number.
37
Section 14.3
Example
5
4
3
2
1
CH3 – CH2 – CH2 – CH – CH3
CH3
 The longest continuous chain of C atoms is five
 Therefore this compound is a pentane derivative with
an attached methyl group


Start numbering from end nearest the substituent
The methyl group is in the #2 position
 The compound’s name is 2-methylpentane.
38
Section 14.3
Substituents in Organic Compounds
Formula
Name
Br –
Cl –
F–
I–
CH3 –
Bromo
Chloro
Fluoro
Iodo
Methyl
39
Section 14.3
Example - Drawing a Structure from a Name
 Draw the structural formula for
2,3-dimethylhexane.
 Note that the end name is hexane .
 Draw a continuous chain of six carbon (C)
atoms, with four bonds around each.
–C–C–C–C–C–C–
40
Section 14.3
Example - Drawing a Structure from a Name
 Number the C atoms from right to left.
 Attach a methyl group (CH3--) to carbon
number 2 and number 3.

Add necessary H atoms.
 2,3-dimethylhexane
–C–C–C–C–C–C–
6 5 4 3
2
1
41
Section 14.3
Cycloalkanes
 Members of the cycloalkane group possess
rings of carbon atoms.
 They have the general formula CnH2n.
 Each carbon atom is bonded to a total of four
carbon or hydrogen atoms.
 The smallest possible ring consists of
cyclopropane, C3H6.
42
Section 14.3
The First Four Cycloalkanes
Condensed Structural
Formula
Name
Cyclopropane
Cyclobutane
Cyclopentane
Cyclohexane
Note that in the condensed structural formulas, there is a
carbon atom at each corner and enough hydrogens are
assumed to be attached to give a total of four single bonds.
43
Section 14.3
Alkenes
 Members of the alkene group have a double bond




between two carbon atoms.
One hydrogen atom has been removed from two
adjacent carbon atoms, thereby allowing the two
adjacent carbon atoms to form a double bond.
General formula is CnH2n
Begins with ethene (ethylene)
C2H4
44
Section 14.3
Structural Formulas
Functional Groups
Alkenes
Ethene
2 carbons
Alkynes
Ethyne
2 carbons
Propene 3 carbons
Propyne 3 carbons
Butene
Butyne
4 carbons
4 carbons
Pentene 5 carbons
Pentyne 5 carbons
Hexene 6 carbons
Hexyne 6 carbons
Heptene 7 carbons
Heptyne 7 carbons
Octene
Octyne
9 carbons
9 carbons
45
Some Members of the Alkene Series
Name
Molecular Formula
Ethene
C2H4
Propene
C3H6
1-Butene
C4H8
2-Butene
C4H8
1-Pentene
C5H10
46
Section 14.3
Naming Alkenes
 “-ane” suffix for the corresponding alkane is changed
to “-ene” for alkenes.
 A number preceding the name indicates the C atom
on which the double bond starts.

The carbons are numbered such that the double bond
has the lowest number.
 For example, 1-butene and 2-butene
47
Section 14.3
Alkenes
 Alkenes are very Reactive and are termed “unsaturated
hydrocarbons”
 Alkenes will characteristically react with hydrogen to form the
corresponding alkane.
48
Section 14.3
Unsaturated Hydrocarbons
 Unsaturated compounds have double or
triple carbon-carbon bonds and are more
reactive than saturated compounds
 Saturated compounds have only single
carbon-carbon bonds (alkanes and similar
compounds
49
Alkynes
 Members of the alkyne group have a triple bond




between two carbon atoms.
Two hydrogen atoms have been removed from each
of two adjacent carbon atoms, thereby allowing the
two adjacent carbon atoms to form a triple bond.
General formula is CnH2n-2
Begins with ethyne (acetylene)
C2H2
50
Section 14.3
Some Members of the Alkyne
Series
Name
Molecular Formula
Ethyne
C2H2
Propyne
C3H4
1-Butyne
C4H6
2-Butyne
C4H6
1-Pentyne
C5H8
51
Section 14.3
Alkynes are Unsaturated
Hydrocarbons
 Due to the triple carbon bond, each alkyne molecule can react
with two molecules of hydrogen.
52
Section 14.3
Derivatives of Hydrocarbons
 Organic molecule characteristics depend on the
number, arrangement, and type of atoms.
 Functional Group – any atom, group of atoms, or
organization of bonds that determine specific
properties of a molecule


Generally the functional group is the reactive part of
the molecule.
Due to the functional group’s presence, certain
predictable properties ensue.
53
Section 14.4
Alkyl Halides
 Alkyl halides have the general formula R—X, where X
is a halogen and R is an alkyl group
 CFC’s (chlorofluorocarbons) are examples of alkyl
halides.
 A well known CFC is dichlorodifluoromethane



(Freon-12)
Extensively used in the past in cooling devices.
Destroys Ozone layer which protects us from UV rays
54
Section 14.4
Example - Drawing Constitutional Isomers
 Draw the structural formulas for the two alkyl halide
isomers that have the molecular formula C2H4Cl2.
 Recall that C atoms form four bonds, H & Cl form one
bond each.
 Draw a two-carbon backbone.

Add enough bonds so that each C has four.
55
Section 14.4
Example - Drawing Constitutional Isomers
 Note, there are just enough open bonds to attach the four H and
two Cl atoms.
 Fill in the Cl atoms in as many ways as possible.
 Remember that you are constrained by the tetrahedral geometry
(109.5o) of the four C bonds.
• Fill in the open bonds
with H atoms and name
the compounds.
56
Section 14.4
Alcohols
 Alcohols are organic compounds containing the
hydroxyl group, —OH, attached to an alkyl group.

General formula is R—OH
 Their IUPAC (International Union of Pure and Applied
Chemistry) names end in “-ol.”
 The most simple alcohol is methanol

Also called methyl alcohol or wood alcohol.
(poisonous)
57
Section 14.4
Alcohols
 Another common alcohol is ethanol. (CH3CH2OH)
 Also known as ethyl alcohol or grain alcohol
 Least toxic and most important of the alcohols
 Ethanol is used in alcoholic beverages, perfumes,
dyes, and varnishes.
58
Section 14.4
Other Alcohol Examples
 Rubbing alcohol is
another alcohol
example.

Also known as 2hydroxypropane or
isopropyl alcohol
 Ethylene glycol is an
alcohol used widely as an
antifreeze and coolant.
59
Section 14.4
Structural Formulas
Functional Groups
Alcohols
Ethanol 2 carbons
Propanol 3 carbons
Butanol 4 carbons
Pentanol 5 carbons
Hexanole 6 carbons
Heptanol 7 carbons
Octanol 9 carbons
60
Carbohydrates
 Compounds that contain multiple hydroxyl
groups in their molecular structure.

Names end in “-ose”
 Sugars, starches, and cellulose are the most
important carbohydrates.
 Glucose (C6H12O6) and fructose (C6H12O6)
are important sugars.

Note that glucose and fructose are isomers.
61
Section 14.4
Carbohydrates - Sugars
 Fructose is the sweetest of all sugars and is
found in fruits and honey.
 Glucose (also called dextrose) is found in
sweet fruits, such as grapes and figs, in
flowers, and in honey.
 Carbohydrates must be broken down into
glucose for circulation in the blood.
62
Section 14.4
Carbohydrates - Starch
 Starch consists of very long chains (up to
3000 units) of glucose.
 Produced by plants in their seeds, tubers,
and fruits
 When these plants parts are eaten, our
digestive processes covert the starches back
into glucose.
63
Section 14.4
Amines
 Organic compounds that contain nitrogen and are
basic (alkaline) are called amines.
 General formula for an amine is R—NH2.

One or two additional alkyl groups could be attached to
the N atom, in place of H atoms.
 Most simple amines have strong odors.
 Odor from raw fish
 Amine examples include methylamine,
dimethylamine, and trimethylamine.
64
Section 14.4
Carboxylic Acids
 Carboxylic acids contain the carboxyl group .
(–COOH)
 They have the general formula RCOOH.
65
Section 14.4
Carboxylic Acids
 Formic acid is the simplest
carboxylic acid.

This is the substance that
causes the painful sting of
insect bites.
• Vinegar is a 5% solution of
acetic acid.
66
Section 14.4
Esters
 Ester – a compound that has
the following general formula
RCOOR’
 In the general formula for an ester the R and R’ can be
any alkyl group.
•
Although R and R’ can be identical, they are usually
different.
 Contrary to amines, most esters have pleasant odors.
• Many flowers and ripe fruits have fragrances and tastes
due to one or more esters.
67
Section 14.4
Fats
 Fats are a type of ester formed by the
combination of the trialcohol named glycerol
and fatty acids.


Glycerol is CH2(OH)CH(OH)CH2(OH)
Stearic Acid (C17H35COOH) is found in beef
fat, and is a typical fatty acid.
68
Section 14.4
Fats
 Generally fats from animals are solid at room
temperature.
 Fats from plants and fish are generally liquid
at room temperature.
 Liquid fats are referred to as oils.
69
Section 14.4
Soap – Like Dissolves Like
 Soap – the sodium salts of fatty acids
 Generally we want to dissolve stains made by
nonpolar compounds such as grease.
 The polar end of the soap dissolves in water.
 The other end of the soap molecule is long and
nonpolar.


This nonpolar end dissolves in the grease.
The emulsified grease droplets can be rinsed away.
70
Section 14.4
Amides
 Amides are nitrogen-containing organic
compounds with the general formula
RCONHR’.
71
Section 14.4
Amide Formation
 Amide formation is similar to ester formation.
 A carboxylic acid reacts with an amine to form water
and an amide, as shown below.
72
Section 14.4
Amino Acid
 Amino acids are organic compounds that contain
both an amino and carboxyl group.
 Glycine and alanine are the simplest amino acids.
 Proteins are extremely long polyamides, formed by
the condensation of amino acids.


Proteins can range from a few thousand formula units
(insulin) to several million formula units.
Proteins serve as both structural components and
enzymes.
73
Section 14.4
Synthetics
 Attempts to duplicate nature have long been
a goal of chemists.
 Basic formulas and structures became known
as the science of chemistry progressed.
 As attempts were made to synthesize natural
compounds, synthetic compounds were
created.
 Synthetics are materials whose molecules
have no duplicate in nature.
74
Section 14.5
Synthetic Polymers
 Due to the scientific approach, chemists were
able to tailor new molecules for specific
purposes.
 Plastics are probably the best known of this
group of synthetic polymers.
 They can be molded and hardened for many
different purposes.
75
Section 14.5
Synthetic Polymers
 A polymer is a compound of very high
formula mass whose long chain molecules
are made of repeating units.
 Monomer is the fundamental repeating unit of
a polymer.
 There are two major types of polymers:


Addition polymers
Condensation polymers
76
Section 14.5
Addition Polymers
 Addition polymers are formed when molecules of an
alkene monomer add to one another.
 Recall that alkenes have a double bond between two
carbon atoms.
 Under the proper reaction conditions the double bond
opens up and attaches itself by single bonds to two
other monomer molecules.
 Each of these monomers will then in turn attach to
another monomer, and so on and on…
77
Section 14.5
Polymerization of Ethene
 The subscripted n on polyethylene indicates
that the unit shown in brackets is repeated
thousands of times.
 Polyethylene is the simplest of the synthetic
polymers.

It is significantly inert chemically and is used to
make containers.
78
Section 14.5
Polymerization
Polymerization-the making of plastics
Vinyl
79
Teflon
 Teflon is made by the polymerization of
tetrafluoroethene.
 This polymer is a hard, strong, chemically
resistant compound with a high melting point
and very low surface friction.
80
Section 14.5
Example - Drawing an Addition Polymer
 An addition polymer can be prepared from vinylidene
chloride, CH2==CCl2. Draw the structure of the
polymer.
 To form the polymer the double bonds of all the
monomers (CH2==CCl2) must open up and
repeatedly bond to the growing chain of monomers.
 The structure is shown as:
81
Section 14.5
Condensation Polymers
 Condensation polymers are formed from molecules
of two or more reactive groups.

Water is the other product, hence the name
condensation polymers.
 Polyethylene terephthalate (PET) is formed from the
polymerization of tetephthalic acid and ethylene
glycol.
82
Section 14.5
Nylon – A Condensation Polymer
 Nylon was first introduced to the public in 1939 at the
New York World’s Fair.
 Nylon is formed from the polymerization of adipic acid
and hexamethylenediamine.
83
Section 14.5
Velcro
 Velcro is a popular fastener made of nylon.
 The hooks of one surface entangle the loops
of the other surface.
 The inventor noticed how cockleburrs clung
to his clothing.
84
Section 14.5