9.1 Carbon Compounds
Carbon compounds form the
structures of a whale’s cells and
control reactions that take place
in those cells. The instructions for
these processes are stored in
organic compounds.
9.1 Carbon Compounds
An organic compound contains carbon and
hydrogen, often combined with a few other elements
such as oxygen and nitrogen.
There are millions of organic compounds—more than
90 percent of all known compounds.
9.1 Carbon Compounds
Carbon has four valence electrons. A carbon atom
can form
• four single covalent bonds,
• a double bond and two single bonds, or
• a triple bond and a single bond.
Most of the bonds in organic compounds are carbonto-carbon bonds or carbon-to-hydrogen bonds.
9.1 Carbon Compounds
Forms of Carbon
What are three forms of carbon?
Diamond, graphite, and fullerenes are forms
of carbon.
9.1 Carbon Compounds
Forms of Carbon
Diamond
Diamond is an example of a network solid, in
which all the atoms are linked by covalent bonds.
• Covalent bonds connect each carbon atom to four
other carbon atoms.
• The three-dimensional structure is rigid, compact,
and strong.
• Diamond is harder than other substances because
cutting a diamond requires breaking many covalent
bonds.
9.1 Carbon Compounds
Forms of Carbon
Graphite
Graphite is extremely soft and slippery.
• Carbon atoms are arranged in widely spaced layers.
• Within each layer, carbon atoms form strong covalent
bonds with three other carbon atoms.
• Between layers the bonds are weak, so layers slide
easily past one another.
9.1 Carbon Compounds
Forms of Carbon
Fullerenes
Fullerenes are large hollow spheres or cages of
carbon.
On the surface of a 60-carbon fullerene (C60), the
atoms form alternating hexagons and pentagons.
The C60 molecule is called buckminsterfullerene.
9.1 Carbon Compounds
Forms of Carbon
A In diamond, carbon atoms are arranged in a rigid, threedimensional network.
B In graphite, the atoms are arranged in layers.
C In fullerenes, carbon atoms are arranged in hollow spheres.
Diamond
Graphite
Buckminsterfullerene
9.1 Carbon Compounds
Saturated Hydrocarbons
What factors determine the properties of a
hydrocarbon?
A hydrocarbon is an organic compound that
contains only the elements hydrogen and
carbon.
Factors that determine the properties of a
hydrocarbon are the number of carbon
atoms and how the atoms are arranged.
9.1 Carbon Compounds
Saturated Hydrocarbons
In a saturated hydrocarbon, all of the bonds
are single bonds.
 A saturated hydrocarbon contains the maximum
possible number of hydrogen atoms for each
carbon atom.
 Saturated hydrocarbons are also called alkanes.
Their names end in –ane.
9.1 Carbon Compounds
Saturated Hydrocarbons
A hydrocarbon molecule can contain one
carbon atom, as in methane, or more than 30
carbon atoms, as in asphalt.
The carbon atoms can be arranged in a
straight chain, a branched chain, or a ring.
9.1 Carbon Compounds
Saturated Hydrocarbons
Microorganisms in the
stomachs of a cow produce
more than 500 liters of
methane (CH4) per day.
9.1 Carbon Compounds
Saturated Hydrocarbons
Straight Chains
• A molecular formula shows the type and number
of atoms in a molecule of the compound.
• A structural formula shows how those atoms are
arranged.
• The boiling point of a straight-chain alkane
depends on the number of carbon atoms.
Methane and propane are gases at room
temperature. Pentane and octane are liquids.
9.1 Carbon Compounds
Saturated Hydrocarbons
9.1 Carbon Compounds
Saturated Hydrocarbons
9.1 Carbon Compounds
Saturated Hydrocarbons
9.1 Carbon Compounds
Saturated Hydrocarbons
9.1 Carbon Compounds
Saturated Hydrocarbons
Branched Chains
Butane and isobutane both have a molecular
formula of C4H10, but their structural formulas are
different.
9.1 Carbon Compounds
Saturated Hydrocarbons
Compounds with the same molecular formula
but different structural formulas are isomers.
• In isobutane, there is a branch at the point where
a carbon atom bonds to three other carbon
atoms.
• Differences in structure affect some properties of
isomers. Butane boils at –0.5°C, but isobutane
boils at –11.7°C.
9.1 Carbon Compounds
Saturated Hydrocarbons
Rings
Carbon atoms in cyclobutane are linked in a fourcarbon ring.
9.1 Carbon Compounds
Saturated Hydrocarbons
In a cycloalkane, each carbon atom forms
bonds with two other carbon atoms and two
hydrogen atoms.
• So cyclobutane (C4H8) molecules have two fewer
hydrogen atoms than butane (C4H10) molecules.
• Most ring alkanes, or cyclic hydrocarbons, have
rings with five or six carbons.
9.1 Carbon Compounds
Unsaturated Hydrocarbons
What are the three types of unsaturated
hydrocarbons?
A hydrocarbon that contains one or more double
or triple bonds is an unsaturated hydrocarbon.
There are three types of unsaturated
hydrocarbons—alkenes, alkynes, and
aromatic hydrocarbons.
9.1 Carbon Compounds
Unsaturated Hydrocarbons
Alkenes
There is a double bond between the two carbon
atoms in ethene. Hydrocarbons that have one or
more carbon-carbon double bonds are alkenes.
The names of alkenes end in –ene.
9.1 Carbon Compounds
Unsaturated Hydrocarbons
Many fruit-bearing
plants produce ethene
(C2H4), which controls
the rate at which fruits,
such as this tomato,
ripen.
9.1 Carbon Compounds
Unsaturated Hydrocarbons
Alkynes
Ethyne (C2H2) is an alkyne. Alkynes are straightor branched-chain hydrocarbons that have one or
more triple bonds. Alkyne names end in –yne.
9.1 Carbon Compounds
Unsaturated Hydrocarbons
Alkynes are the most reactive hydrocarbon
compounds. Ethyne (C2H2), also known as
acetylene, is used in torches that cut metal or
weld them together.
9.1 Carbon Compounds
Unsaturated Hydrocarbons
Aromatic Hydrocarbons
Benzene (C6H6) is an
unsaturated hydrocarbon with
a ring structure.
9.1 Carbon Compounds
Unsaturated Hydrocarbons
Although the formula for Benzene shows
alternating single and double bonds, the six
bonds in the ring are identical. All six carbon
atoms share six of the valence electrons.
Hydrocarbons that contain similar ring
structures are known as aromatic
hydrocarbons. The name was chosen
because many of these compounds have
strong aromas, or odors.
9.1 Carbon Compounds
Fossil Fuels
What are the three main fossil fuels?
Three types of fossil fuels are coal, natural
gas, and petroleum.
Fossil fuels are mixtures of hydrocarbons that
formed from the remains of plants or animals.
9.1 Carbon Compounds
Fossil Fuels
Coal
• Giant tree ferns and other plants were buried in
swamps.
• After millions of years of pressure, the plant
remains produced a mixture of hydrocarbons.
• Most of the hydrocarbons in coal are aromatic
hydrocarbons with high molar masses.
• Coal produces more soot than other fossil fuels.
9.1 Carbon Compounds
Fossil Fuels
The ferns shown are similar to ferns that lived
millions of years ago. Imprints of ferns in coal
are evidence that coal formed when plant
remains were compressed.
9.1 Carbon Compounds
Fossil Fuels
Natural Gas
• Natural gas formed from the remains of marine
organisms.
• The main component of natural gas is methane.
Natural gas also contains ethane, propane, and
isomers of butane.
• Natural gas is used for heating and cooking.
• Deposits of natural gas are found along with
coal and petroleum.
9.1 Carbon Compounds
Fossil Fuels
Petroleum
• Petroleum also formed from marine organisms.
• Petroleum is pumped from deep beneath Earth’s
surface.
• Petroleum is a complex liquid mixture of
hydrocarbons, mainly long-branched alkanes
and alkenes.
9.1 Carbon Compounds
Fossil Fuels
Petroleum is separated into mixtures called
fractions.
Distillation Tower
Heating Burner
9.1 Carbon Compounds
Fossil Fuels
Petroleum is separated into mixtures called
fractions.
Distillation Tower
Heating Burner
9.1 Carbon Compounds
Fossil Fuels
Petroleum is separated into mixtures called
fractions.
Distillation Tower
Crude oil
Heating Burner
9.1 Carbon Compounds
Fossil Fuels
Petroleum is separated into mixtures called
fractions.
Distillation Tower
Crude oil vapors
Crude oil
Heating Burner
9.1 Carbon Compounds
Fossil Fuels
Petroleum is separated into mixtures called
fractions.
Distillation Tower
Crude oil vapors
Crude oil
Heating Burner
9.1 Carbon Compounds
Fossil Fuels
Petroleum is separated into mixtures called
fractions.
Distillation Tower
Crude oil vapors
Crude oil
Heating Burner
9.1 Carbon Compounds
Fossil Fuels
Petroleum is separated into mixtures called
fractions.
Distillation Tower
Crude oil vapors
Crude oil
Heating Burner
9.1 Carbon Compounds
Fossil Fuels
Petroleum is separated into mixtures called
fractions.
Distillation Tower
Crude oil vapors
Crude oil
Heating Burner
9.1 Carbon Compounds
Fossil Fuels
Petroleum is separated into mixtures called
fractions.
Distillation Tower
Crude oil vapors
Crude oil
Heating Burner
9.1 Carbon Compounds
Combustion of Fossil Fuels
What are the two primary products of the
combustion of fossil fuels?
The primary products of the complete
combustion of fossil fuels are carbon
dioxide and water.
C3H8 + 5O2  3CO2 + 4H2O (complete combustion)
9.1 Carbon Compounds
Combustion of Fossil Fuels
Incomplete Combustion
If there is not enough oxygen available for complete
combustion of all the fuel, carbon monoxide is produced.
Carbon monoxide is a colorless, odorless gas that is
poisonous. It keeps hemoglobin from carrying oxygen to
cells.
2C3H8 + 7O2  6CO + 8H2O (incomplete combustion)
9.1 Carbon Compounds
Combustion of Fossil Fuels
Acid Rain
Sulfur dioxide and nitrogen
oxides released into the
atmosphere by the combustion of
fossil fuels forms sulfuric acid
and nitric acid.
These acids damage stone
structures, metal, and concrete.
9.1 Carbon Compounds
Assessment Questions
1. Graphite is soft and slippery because its carbon
atoms
a. are arranged in layers with weak attractions between
layers.
b. have a large, interlocking network.
c. contain individual atoms with very weak bonds to other
carbon atoms.
d. share a weak bond with hydrogen atoms.
9.1 Carbon Compounds
Assessment Questions
1. Graphite is soft and slippery because its carbon
atoms
a. are arranged in layers with weak attractions between
layers.
b. have a large, interlocking network.
c. contain individual atoms with very weak bonds to other
carbon atoms.
d. share a weak bond with hydrogen atoms.
ANS: A
9.1 Carbon Compounds
Assessment Questions
2. In general, the boiling point of a hydrocarbon
increases as
a. the number of hydrogen bonds between molecules
increases.
b. the number of carbon atoms in the chain increases.
c. the branching of the carbon chain increases.
d. the number of oxygen atoms in the molecule increases.
9.1 Carbon Compounds
Assessment Questions
2. In general, the boiling point of a hydrocarbon
increases as
a. the number of hydrogen bonds between molecules
increases.
b. the number of carbon atoms in the chain increases.
c. the branching of the carbon chain increases.
d. the number of oxygen atoms in the molecule increases.
ANS: B
9.1 Carbon Compounds
Assessment Questions
3. An unsaturated hydrocarbon always contains
a.
b.
c.
d.
double bonds between carbon atoms.
double or triple bonds.
at least one ring in its structure.
at least one atom that is neither carbon nor hydrogen.
9.1 Carbon Compounds
Assessment Questions
3. An unsaturated hydrocarbon always contains
a.
b.
c.
d.
double bonds between carbon atoms.
double or triple bonds.
at least one ring in its structure.
at least one atom that is neither carbon nor hydrogen.
ANS: B
9.1 Carbon Compounds
Assessment Questions
4. A hydrocarbon in which two of the carbon atoms
are joined by a triple covalent bond is an
a.
b.
c.
d.
alkane.
alkene.
alkyne.
aromatic hydrocarbon.
9.1 Carbon Compounds
Assessment Questions
4. A hydrocarbon in which two of the carbon atoms
are joined by a triple covalent bond is an
a.
b.
c.
d.
alkane.
alkene.
alkyne.
aromatic hydrocarbon.
ANS: C
9.1 Carbon Compounds
Assessment Questions
5. Most of the hydrocarbon compounds in coal are
a.
b.
c.
d.
short-chain alkanes.
long-chain unsaturated hydrocarbons.
cycloalkanes.
aromatic hydrocarbons.
9.1 Carbon Compounds
Assessment Questions
5. Most of the hydrocarbon compounds in coal are
a.
b.
c.
d.
short-chain alkanes.
long-chain unsaturated hydrocarbons.
cycloalkanes.
aromatic hydrocarbons.
ANS: D
9.1 Carbon Compounds
Assessment Questions
6. Which of these compounds is formed during the
combustion of fossil fuels and then reacts with
water in the air to form acid rain?
a.
b.
c.
d.
carbon dioxide
sulfur dioxide
iron (II) oxide
ozone
9.1 Carbon Compounds
Assessment Questions
6. Which of these compounds is formed during the
combustion of fossil fuels and then reacts with
water in the air to form acid rain?
a.
b.
c.
d.
carbon dioxide
sulfur dioxide
iron (II) oxide
ozone
ANS: B
9.1 Carbon Compounds
Assessment Questions
1. Carbon forms the backbone structure of millions of
different organic compounds because each
carbon atom forms four covalent bonds with other
atoms.
True
False
9.1 Carbon Compounds
Assessment Questions
1. Carbon forms the backbone structure of millions of
different organic compounds because each
carbon atom forms four covalent bonds with other
atoms.
True
False
ANS:
T
9.1 Carbon Compounds
Assessment Questions
2. The compound that is an indicator of incomplete
combustion of hydrocarbons is carbon dioxide.
True
False
9.1 Carbon Compounds
Assessment Questions
2. The compound that is an indicator of incomplete
combustion of hydrocarbons is carbon dioxide.
True
False
ANS:
F, carbon monoxide