Chapter 22
Carbon & Hydrocarbons
Chapter 22 Vocabulary
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Diamond
Graphite
Fullerenes
Delocalized electrons
Organic compounds
Catenation
Hydrocarbons
Isomers
Structural formula
Structural isomers
Geometric isomers
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Saturated hydrocarbon
Alkanes
Cycloalkanes
Alkyl groups
Natural gas
Petroleum
Unsaturated hydrocarbons
Alkynes
Aromatic hydrocarbons
benzene
Chapter 22 Vocabulary
• Diamond is a colorless, crystalline, solid form of carbon
• Graphite is a soft, black, crystalline form of carbon that is a
fair conductor of electricity
• Fullerenes are dark colored solids made of spherically
networked carbon atom cages.
• Delocalized electrons are electrons shared by more than
two atoms
• Organic compounds covalently bonded compounds
containing carbon, excluding carbonates and oxides.
• Catenation the covalent bonding of an element to itself to
form chains or rings.
• Hydrocarbons are composed of only carbon and hydrogen;
they are the simplest organic compounds.
• Compounds that have the same molecular formula but
different structures are called isomers.
• Structural formula indicates the number and types of
atoms present in a molecule and also shows the bonding
arrangement of the atoms.
Chapter 22 Vocabulary
• Structural isomers are isomers in which the atoms are bonded
together in different orders.
• Geometric isomers are isomers in which the order of atom bonding
is the same but the arrangement of atoms in space is different.
• Saturated hydrocarbons are hydrocarbons in which each carbon
atom in the molecule forms four single covalent bonds with other
atoms.
• Hydrocarbons that contain only single bonds are alkanes.
• Cycloalkanes are alkanes in which the carbon atoms are arranged in
a ring, or cyclic, structure.
• Alkyl groups are groups of atoms that are formed when one
hydrogen atom is removed from an alkane molecule
• Natural gas is a fossil fuel composed primarily of alkanes containing
one to four carbon atoms
• Petroleum is a complex mixture of different hydrocarbons that varies
greatly in composition.
• Unsaturated hydrocarbons are hydrocarbons in which not all
carbon atoms have four single covalent bonds.
Chapter 22 Vocabulary
• Structural isomers are isomers in which the atoms are
bonded together in different orders.
• Geometric isomers are isomers in which the order of
atom bonding is the same but the arrangement of atoms
in space is different.
• Alkenes are hydrocarbons that contain double covalent
bonds.
• Hydrocarbons with triple covalent bonds are alkynes.
• Aromatic hydrocarbons are hydrocarbons with six
membered carbon rings and delocalized electrons
• Benzene is the primary aromatic hydrocarbon
Alkanes and Aromatic Hydrocarbons
Organic Compounds
Bonding in Hydrocarbons
Naming Alkanes
Properties of Alkanes
Organic Chemistry and
Hydrocarbons
• _________ originally meant chemicals
that came from ______________.
• 1828 German chemist Friedrich
Wohler synthesized urea in a lab
• Today, organic chemistry is the
chemistry of virtually all compounds
containing the element ___________.
Friedrich Wohler
1800 – 1882
Used inorganic
substances to
synthesize urea, a
carbon compound
found in urine.
This re-defined
organic chemistry.
Organic Chemistry and
Hydrocarbons
• Over a million organic
compounds, with numerous
properties
• Why so many? Carbon’s unique
bonding ability!
• Let’s start with the simplest of the
organic compounds:
Hydrocarbons
Organic Compounds
 Contain
_________________
 Have
______________ bonds
 Have
low _____________ points
 Have
low _______________ points
 Burn
in air (oxygen)
 Are
soluble in _____________ solvents
 Form
large ________________
Alkanes

Contain ______ and _________ only

Contain ____________ bonds C-C

Have _____ bonds to every carbon (C) atom

Are ________________
Alkanes
Structural Formulas
Show the bonds between each of the
atoms
H
H

HCH
H
C

H
H
CH4 - methane
H
Alkanes
Structural Formulas
H
H
H
H
C
C
H
H
Condensed Structural Formulas
H
CH3
CH3
Ethane
H
H
H
C
C
C
H
H
H
H
CH3 CH2 CH3
Propane
Alkanes
Structural Formulas
H
CH3
H
H
H
C
C
C
H
H
H
CH2
CH3CH2CH3
H
CH3
Structural Formula
Condensed Structural Formula
Condensed Formula
Alkanes
Structural Formulas
Examples:
_____________ formula
Condensed__________________
Alkanes
Organic Naming Prefixes
Naming Alkanes
Name
# carbons
Structural Formula
____ane 1
CH4
____ane 2
CH3CH3
____ane 3
CH3CH2CH3
____ane 4
CH3CH2CH2CH3
____ane 5
CH3CH2CH2CH2CH3
Naming Alkanes
Name # carbons
Structural Formula
___ane 6
CH3CH2CH2CH2CH2CH3
____ane 7
CH3CH2CH2CH2CH2CH2CH3
___ane
8
CH3CH2CH2CH2CH2CH2CH2CH3
___ane 9
CH3 CH2 CH2CH2CH2CH2CH2CH2CH3
___ane 10 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3
Practice Problems
A. What is the condensed formula for
H H H H
H
C
C
C
C
H
H
H
H
H
B. What is its molecular formula?
C. What is its name?
Reactions of Alkanes
Combustion
alkane + O2
CO2 + H2O + heat
Combustion In the Cell
Metabolic oxidation is combustion
C6H12 O6 + 6O2
glucose
6CO2 + 6H2O + heat
Combustion Example
Complete the combustion reaction for
C 3H 8 + O 2
Balance your equation
+
Practice Problem
Complete and balance the reaction for
the complete combustion of C7H16
Alkanes and Aromatic Hydrocarbons
Branched Alkanes
Structural Formulas
Alkyl Groups
Branches on carbon chains
H
H
H
C
H
H
H
C
C
H
H
CH3
_________
CH3CH2
_________
Alkyl Groups
Branched Alkanes
CH3
CH3CHCH3
methyl groups
CH3
CH3
CH3CHCH2CHCH3
Naming Branched Alkanes
CH3
methyl branch
CH3CH2CH2CHCH2CH3
6
5
4
3
2
1
Count
Naming Branched Alkanes
CH3
methyl branch
CH3CH2CH2CHCH2CH3
6
5
4
3
2
1
Count
3-Methylhexane
on third C
CH3
group
six carbon chain
Naming Alkanes
Naming Alkanes Example
Naming Practice Problems
A.
CH3
CH3
CH3CHCH2CHCH3
B.
CH3
CH3
CH3CH2CHCH2CCH2CH3
CH3
Practice Problems
Write a condensed structure for
A. 3,4-dimethylheptane
B.
2,2-dimethyloctane
Isomers
• Same _____________ formula
• Same ________ and ______ of atoms
• Different ________________ of atoms
• Also have different properties, such as
b.p., m.p., and reactivity
Structural Isomers
___________________ are isomers in which
the atoms are bonded together in different
orders.
Geometric Isomers
•____________________ are isomers in
which the order of atom bonding is the
same but the arrangement of atoms in
space is different.
Examples of Isomers
The formula C4H10 has two different structures
CH3
CH3CH2CH2CH3
Butane
CH3CHCH3
2-methylpropane
When a CH3 is is used to form a branch, it
makes a new isomer of C4H10.
Practice Problem
Write 3 isomers of C5H12 and name each.
Practice Problems
Write the structural formulas of 3 isomers
that have the formula C5H12. Name each.
Alkanes and Aromatic Hydrocarbons
Cycloalkanes
Aromatic Hydrocarbons
Cycloalkanes
_____________
CH2
CH2
CH2
_____________
CH2
CH2
CH2
CH2
More Cycloalkanes
____________
CH2
CH2
CH2
CH2
CH2
____________
CH2
CH2 CH2
CH2
CH2
CH2
Naming Cycloalkanes with Side Groups
Number of
side groups
One
Naming
Two or more
Number the ring in the direction
that gives the lowest numbers
to the side groups.
Side group name goes in front
of the cycloalkane name.
Cycloalkanes with Side Groups
CH3
methylcyclopentane
CH3
CH3
1,2-dimethylcyclopentane
CH3
CH3
1,2,4-trimethylcyclohexane
CH3
Practice Problems
CH3
CH3
CH3
CH3
CH3
Aromatic Compounds and Benzene
___________________ contain __________.
Benzene, C6H6 , is represented as a ______
carbon ring with _____ double bonds.
Two possible can be drawn to show benzene
in this form.
H
H
H
H
H
H
H
H
H
H
H
H
Benzene Structure
The structures for ______________ can also
be written as a single structure where the
alternating double bonds are written as a
circle within the ring.
Benzene
structure
Aromatic Compounds in Nature and Health
Many aromatic compounds are common in
_____________ and in _____________.
CHO
COOH
COOCH3
CH3
CH3
CH3CHCH2
CHCOOH
OCH3
OH
Aspirin
Vanillin
Ibuprofen
Naming Aromatic Compounds
Aromatic compounds are named with benzene
as the parent chain. One side group is named in
front of the name benzene.
CH3
methylbenzene
(toluene)
Cl
chlorobenzene
Naming Aromatic Compounds
When two groups are attached to benzene, the
ring is numbered to give the lower numbers to the
side groups. The prefixes ortho (1,2), meta (1,3-)
and para (1,4-) are also used.
Cl
CH3
Cl
CH3
1,2-dimethylbenzene
(ortho-dimethylbenzene)
Cl
1,3-dichlorobenzene
(meta-dichlorobenzene)
CH3
1-chloro-4-methylbenzene
(para-chloromethylbenzene)
Some Common Names
Some substituted benzene rings also use a
common name. Then naming with additional more
side groups uses the ortho-, meta-, para- system.
CH3
OH
CH3
Cl
Toluene
(Methylbenzene)
meta-chlorotoluene
(meta-chloromethylbenzene)
phenol
(hydroxybenzene)
Practice Problems
Write the structural formulas for each of the
following:
A. 1,3-dichlorobenzene
B. Ortho-chlorotoluene
Practice Problems
Select the names for each structure:
Cl
1. Chlorocyclohexane
2. Chlorobenzene
3. 1-chlorobenzene
CH3
1. Meta-methyltoluene
2. Meta-dimethylbenzene
3. 1,3-dimethylbenzene
CH3
Haloalkanes, Alkenes, and Alkynes
Alkenes and Alkynes
Saturated and Unsaturated Compounds
Saturated compounds (alkanes) have
the maximum number of hydrogen
atoms attached to each carbon atom
Unsaturated compounds have fewer
hydrogen atoms attached to the carbon
chain than alkanes
Unsaturated compounds contain double
or triple bonds alkenes & alkynes
Alkenes
Carbon-carbon _____________ bonds
Names end in -___________
H2C=CH2
ethene (ethylene)
H2C=CH-CH3
propene (propylene)
cyclohexene
Alkenes
Alkynes
Carbon-carbon __________ bonds
Names end in -_________
HCCH
ethyne(acetylene)
HCC-CH3
propyne
Naming Alkenes and Alkynes
When the carbon chain has 4 or more C atoms,
number the chain to give the lowest number to the
double or triple bond.
1
2 3 4
CH2=CHCH2CH3
1-butene
CH3CH=CHCH3
2-butene

2-butyne
CH3CH CHCH3
Naming Alkenes
Slide 35
Naming Alkenes
Naming Alkynes
Slide 35
Practice Problem
Write the names for each of the following
unsaturated compounds:
A.
CH3CH2CCCH3
CH3
CH3
B.
CH3C=CHCH3
C.
Hydrogenation
Adds a hydrogen atom to each carbon
atom of a double bond
H H
H H
Ni
H–C=C–H + H2
H–C–C–H
H H
ethene
ethane
Products of Hydrogenation
Adding H2 to vegetable oils produces
compounds with higher melting points
 Margarines
 Soft margarines
 Shortenings (solid)
Trans Fats
In the US, it is estimated that 2-4% of our total
Calories is in the form of trans fatty acid.
trans fatty acids behave like saturated fatty
acids in the body.
Several studies reported that trans fatty acids
raise LDL-cholesterol. Some studies also
report that trans fatty acid lower HDLcholesterol
The trans fatty acids controversy will continue
to be debated.
Unsaturated Fatty Acids
 Fatty acids in vegetable oils are omega-6 acids
(the first double bond occurs at carbon 6 counting
from the methyl group)
 A common omega-6 acid is linoleic acid
CH3CH2CH2CH2CH2CH=CHCH2CH=CH(CH2)7COOH
6
linoleic acid, a fatty acid
Trans Fats
In vegetable oils, the unsaturated fats usually
contain cis double bonds.
During hydrogenation, some cis double bonds
are converted to trans double bonds (more
stable) causing a change in the fatty acid
structure
If a label states “partially” or “fully
hydrogenated”, the fats contain trans fatty
acids.
Fats and Atheroschlerosis
 Inuit people of Alaska have a high fat diet
and high blood cholesterol levels, but a
very low occurrence of atherosclerosis
and heart attacks.
 Fat in the Intuit diet was primarily from
fish such as salmon, tuna and herring
rather than from land animals (as in the
American diet).
Omega-3 Fatty Acids
 Fatty acids in the fish oils are mostly the omega-3
type (first double bond occurs at the third carbon
counting from the methyl group).
 linolenic acid 18 carbon atoms
CH3CH2CH=CHCH2CH=CHCH2CH=CH(CH2)7COOH

 eicosapentaenoic acid (EPA) 20 carbon atoms
CH3CH2(CH=CHCH2)5(CH2)2COOH
Atherosclerosis
 Plaques of cholesterol adhere to the walls of the
blood vessels
 Blood pressure rises as blood squeezes through
smaller blood vessels
 Blood clots may form
 Omega-3 fatty acids decrease the “sticking” of
blood platelets (fewer blood clots)
 Omega-3 fatty acids can increase bleeding time
Questions
(1) Ture or (2) False
A. ____ There are more unsaturated fats in
vegetable oils.
B. ____ Vegetable oils have more omega-3 oils
than found in fish.
C. ____ Hydrogenation of oils converts some
cis-double bonds to trans- double bonds.
D. ____ Animal fats have more saturated fats.
Natural Gas
• Fossil fuels provide much of the
world’s energy
• Natural gas and petroleum contain
mostly the aliphatic (or straight-chain)
hydrocarbons – formed from marine
life buried in sediment of the oceans
• Natural gas is an important source of
alkanes of low molecular mass
Natural Gas
• Natural gas is typically:
–80% methane, 10% ethane, 4%
propane, and 2% butane with the
remainder being nitrogen and
higher molar mass hydrocarbons
–also contains a small amount of
He, and is one of it’s major
sources
Natural Gas
• Natural gas is prized for
combustion, because with
adequate oxygen, it burns with a
hot, clean blue flame:
– CH4 + 2O2  CO2 + 2H2O + heat
• Incomplete burning has a yellow
flame, due to glowing carbon parts,
as well as making carbon monoxide
Petroleum
• The compounds found in petroleum
(or crude oil) are more complex
than those in natural gas
• Usually straight-chain and
branched-chain alkanes, with some
aromatic compounds also
• Crude oil must be refined
(separated) before being used
Petroleum
• It is separated by distillation into
fractions, according to boiling pt.
• Fractions containing higher molar
mass can be “cracked” into more
useful shorter chain components,
such as gasoline and kerosene
– involves catalyst and heat
– starts materials for plastics and paints
Citations
• http://www.karentimberlake.com/
• http://www.cottonchemistry.bizland.com/
chem/chemnotes1.htm