3/24/2016
Dr Seemal Jelani
1
Chem-160
CH.2
HYDROCARBONS
OBJECTIVES
3/24/2016
What are hydrocarbons? What structural features identify
alkanes? Alkenes? Alkynes? Aromatic hydrocarbons?
 How are alkanes, alkenes, alkynes, and aromatic
hydrocarbons named using IUPAC nomenclature?
 What are the physical and chemical properties of
alkanes, alkenes, alkynes, and aromatic hydrocarbons?
Dr Seemal Jelani

Chem-160
2
OBJECTIVES
3/24/2016
 What
Dr Seemal Jelani
is an alkyl group?
 What are some products from reactions of
alkanes? How are they formed?
 What are the major reactions of alkenes? What
are the products of those reactions?
 What are polymers? How are they formed and
utilized?
 What is petroleum and how is it utilized?
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PROPERTIES
Organic (Benzene)
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High melting pts
High boiling pts
Soluble in water
Nonflammable
Conductive
Ionic bonds
Chem-160

Inorganic (NaCl)
Dr Seemal Jelani

Low melting pts
Low boiling pts
Low solubility in
water
Highly flammable
Nonconductive
Covalent bonds
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4
HYDROCARBONS
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
Compounds containing only two elements

Carbon and hydrogen
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Chem-160
5
ALKANES: STRUCTURES AND
NAMES
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Dr Seemal Jelani
Objectives
 Identify an alkane
 Determine what an isomer of an alkane is
 Identify different types of alkanes
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ALKANES
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Saturated Hydrocarbons
 Called saturated because each carbon is bonded
to four other atoms
 Only single bonds
 Methane
 Ethane
 Propane

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HOMOLOGY
3/24/2016
Related compounds
 Homologs

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Have properties that vary in a regular and
predictable manner
 A manner of organization
 Similar to P.T.

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ISOMERS
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Different compounds having the same molecular
formula
 Butane
 Isobutane (isolated branched chain)

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Chem-160
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ISOMERS
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Pentane
 Isopentane
 Neopentane

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ALKANES
Dr Seemal Jelani
Structural Formulas
 Condensed Structural Formulas
 Butane

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CnH2n+2
 Representation

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ALKYL GROUP
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Dr Seemal Jelani
Chem-160
A group of atoms that results when one hydrogen
atom is removed from an alkane
 CnH2n+1
 Change –ane ending to –yl
 Methyl
 Ethyl
 Propyl

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IUPAC NOMENCLATURE
3/24/2016
Dr Seemal Jelani
Define IUPAC
 Examine the rules for IUPAC naming
 Determine the correct names of alkanes
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IUPAC NOMENCLATURE
(isobutane, isopentane are common names)
Dr Seemal Jelani
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3/24/2016
Geneva, Switzerland 1892
 International Union of Pure and Applied
Chemistry
 IUPAC System of Nomenclature

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14
IUPAC RULES
1. Name the longest chain in the parent compound.
End in –ane. (Root name)

Must use the lowest number possible.
Chem-160
2. Note the alkyl groups attached
 3. Number the carbon that the group is attached to.

Dr Seemal Jelani
Number each carbon
 See Example
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IUPAC RULES CON’T
4. Use prefixes to indicate the amount of
attached groups
See Example
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5. If there are more than two or more different
substituents, list them in alphabetical order.
 If at equal points, lower alphabetical order given
lowest number
 Prefixes not included in alphabetizing

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16
Name each of the following
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Chem-160
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Name each of the following
B.
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A.
Dr Seemal Jelani
Chem-160
C.
D.
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Answers
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Dr Seemal Jelani
a. 3-ethylhexane
b. 2,4-dimethylpentane
c. c. 3-methylhexane
d. 4-isopropylheptane
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DRAW THE STRUCTURAL FORMULAS FOR
EACH OF THE FOLLOWING
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Dr Seemal Jelani
4-propylheptane
 3-ethyl-2-methylpentane
 3-isopropyl-3-methyloctane

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ANSWERS
3/24/2016

Dr Seemal Jelani
Chem-160
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SEC. 13.3
PROPERTIES OF ALKANES
Objectives

Dr Seemal Jelani
Determine the physical and physiological properties
of alkanes
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
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PHYSICAL PROPERTIES

Insoluble in water

Less than 1.0g/ml
Related to one another

See chart
Boiling points


Increase with higher molar mass
Chem-160

Dr Seemal Jelani
Less dense than water
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Nonpolar
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PHYSIOLOGICAL PROPERTIES
Heavy liquids
Mineral oil
 Petroleum jelly

Chem-160

Dr Seemal Jelani
Light liquids
 Harmful to lungs
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Gases serve as anesthetics
 Liquid alkanes
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Objectives

Determine the chemical properties of alkanes
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SEC. 13.4
CHEMICAL PROPERTIES: REACTIONS OF
ALKANES
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CHEMICAL PROPERTIES
Undergo combustion reactions
CH4 + 2 O2  CO2 + 2 H2O + Heat
Chem-160
2 CH4 + 3 O2  2 CO + 4 H2O
(Harmful carbon monoxide reaction)
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Do not react with many laboratory agents
 Usually very flammable
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SEC. 13.5
HALOGENATED HYDROCARBONS
Objectives
Dr Seemal Jelani
Define what halogenated hydrocarbons are
 Name halogenated hydrocarbons using common and
IUPAC names
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HALOGENATED HYDROCARBONS
Have one or more hydrogen atoms replaced by
halogen atoms

Results in an alkyl halide
Chem-160
Usually these are formed under UV light or very high
temps
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COMMON NAMES
Name these:
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

Chem-160

CH3CH2Br
(CH3)2CHCl
CH3I
CH3CH2CH2F
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First part of name is alkyl group
 Second part is the halogen, ending in –ide
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ANSWERS
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Dr Seemal Jelani
Ethyl bromide
 Isopropyl chloride
 Methyl iodide
 Propyl flouride

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IUPAC NAMES
3/24/2016
Dr Seemal Jelani
Rules similar to those used for naming alkanes
 Substitute in the prefixes fluoro-, chloro-, bromo-,
and iodo
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GIVE THE IUPAC NAME FOR EACH OF THE
FOLLOWING COMPOUNDS
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ANSWERS
3/24/2016
Dr Seemal Jelani
2-chloropentane
 4-bromo-2-methylhexane
 2-chloro-3-methylbutane
 1-bromo-3-chloro-4-methylpentane

Chem-160
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SEC. 13.6
CYCLOALKANES
3/24/2016
Dr Seemal Jelani
Define what a cycloalkane is
 Name and draw cycloalkanes

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CYCLOALKANES
Another: cyclohexane
Dr Seemal Jelani
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3/24/2016
Carbon atoms that are joined in a ring or circle
 Simplest: cyclopropane

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NAMING
Draw structures for the following compounds


Chem-160

Cyclooctane
Ethylcyclohexane
1,1,2-trimethylcyclobutane
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Add cyclo Otherwise fairly similar to regular naming
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ANSWERS
Dr Seemal Jelani
Chem-160
C.
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B.

A.

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DRAW THESE STRUCTURES
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Dr Seemal Jelani
Cyclopentane
 1-ethyl-2-methylcyclopentane
 1-ethyl-1,2,5,5-tetramethylcycloheptane

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ANSWERS
B.

C.
Chem-160

Dr Seemal Jelani
A.
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SEC. 13.7
ALKENES
Objectives
Dr Seemal Jelani
Define alkene
 Name alkenes using IUPAC rules
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
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ALKENES
Chem-160
Have a double bond (CH3=CH2)
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End in -ene
 Unsaturated hydrocarbons
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IUPAC RULES
2.
Chem-160
5-methyl-2-hexene
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3.
Name the longest chain.
Indicate the position of the double bond with
the lowest number possible.
Substituent groups named like alkanes
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1.
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NAME EACH OF THE FOLLOWING
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ANSWERS
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Dr Seemal Jelani
6-dimethyl-2-heptene
 2-ethyl-1-butene
 4-ethyl-2-methyl-2-hexene
 1-methylcyclohexene
 2,4,4-trimethyl-2-pentene

Chem-160
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DRAW THE STRUCTURE FOR THE
FOLLOWING
3/24/2016
Dr Seemal Jelani
3,4-dimethyl-2-pentene
 3-ethyl-2-methyl-1-hexene
 3-isopropylcyclopentene

Chem-160
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ANSWERS
B.

C.
Chem-160

Dr Seemal Jelani
A.
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
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SEC. 13.8
PROPERTIES OF ALKENES
Objectives

Determine the properties of alkenes
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
Dr Seemal Jelani
Chem-160
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PROPERTIES OF ALKENES
to alkanes
widely in nature
 Ethylene

 Others

Carotene


Chem-160

Triggers fruit ripening
Can be used artifically
Dr Seemal Jelani
 Occur
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 Similar
Vitamin A
Fruit coloring
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Dr Seemal Jelani
Define addition reactions
 Discuss hydrogenation and hydration
 Write equations for reactions between alkenes and
other substances
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SEC. 13.9
CHEMICAL PROPERTIES: REACTIONS OF
ALKENES
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ADDITION REACTIONS
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of the bonds in the double bond is
broken and each of the involved carbon
atoms then bonds to another atom or
group
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 One
Chem-160
 Hydrogenation—addition
an unsaturated molecule
of hydrogen to
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HALOGEN ADDITION
Alkenes readily add halogen molecules
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HYDRATION
Addition of water to an alkene
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EQUATIONS
3/24/2016
Dr Seemal Jelani
Write equations for the reaction between
CH3CH=CHCH3 and each of the following
 H2
 Br2
 H2O (H2SO4 catalyst)

Chem-160
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ANSWERS
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Dr Seemal Jelani
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54
with each of the
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Dr Seemal Jelani
Write equations for the reaction of
following.
 H2 (Ni catalyst)
 Cl2
 H2O (H2SO4 catalyst)

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ANSWERS
.
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56
SEC. 13.11
ALKYNES
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Dr Seemal Jelani
Define alkyne
 Name alkynes using IUPAC naming rules

Chem-160
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ALKYNES
have similar properties to those
of alkanes and alkenes
 Naming is the same, except they end in
-yne
Chem-160
 Alkynes
Dr Seemal Jelani
atoms share 3 pairs of electrons,
forming a triple bond
 Acetylene
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 Carbon
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SEC. 13.12
BENZENE
Objectives

Recognize the versatile structure of a benzene ring
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Dr Seemal Jelani
Chem-160
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BENZENE
3/24/2016
Dr Seemal Jelani
Chem-160
Recognized by Michael Faraday in 1825
 Six sided structure with single and double mobile
bonds
 Resonance—a word used to describe the
phenomenon in which noFigure
single Lewis structure
13.13
can be used
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3/24/2016
SEC. 13.13
STRUCTURE AND NOMENCLATURE OF
AROMATIC COMPOUNDS
Dr Seemal Jelani
Chem-160
Define and name aromatic hydrocarbons and aliphatic
compounds
 Determine the difference between ortho, meta, and
para distribution
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AROMATIC COMPOUNDS
3/24/2016
Dr Seemal Jelani
Benzene
 Named because thought to have strong aroma
 Now define as anything that has a benzene ring
 Aliphatic compounds—nonaromatic

Chem-160
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NAMING
3/24/2016
One substituent…easy

Dr Seemal Jelani
Chem-160
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NAMING
Dr Seemal Jelani
Chem-160
Ortho (1,2 distribution)
 Meta (1,3 distribution)
 Para (1,4 distribution)
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2 substituents…2 different ways
 One way…same as before
 Other way…uses the terms ortho, meta, and para
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EXAMPLES
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Dr Seemal Jelani
Chem-160
65
ARYL GROUPS
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Dr Seemal Jelani
Sometimes Benzene rings attach to alkanes or
alkenes
 Known as aryl groups
 Most common one is phenyl

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Objectives

Discuss some of the uses of benzene
Dr Seemal Jelani
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3/24/2016
SEC. 13.14
USES OF BENZENE AND BENZENE DERIVATIVES
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USES OF BENZENE



Tryptophan
Vitamin K
Folic acid
Many drugs…Table 13.12
Chem-160

Dr Seemal Jelani
comes from petroleum
 Used as a starting material
 Added to fuels to improve octane rating
 Cigarette smoke
 Very toxic
 In Nature..
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 Most
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