Transcript Slide 1

Chapter
#20
Carbon and
Hydrocarbons
NearingZero.net
Chapter 20.1
• Carbon is found in nature both as an
element and in combined form.
• 17th abundant element in the Earth’s
crust by mass.
• Found in all living things, tissue and in
the foods we eat.
• Is also found in fuels (coal,
petroleum, natural gas, wood.)
Allotropes of carbon
1. Diamond is a colorless, crystalline, solid form of
carbon.
• Hardest material known.
• Most dense form of carbon.
• Extremely high melting point ( 3500*C)
• Used industrially for cutting, drilling, and grinding
2. Graphite is a soft, black, crystalline form of
carbon that conducts electricity.
• Feels greasy and crumbles easily.
• Used in pencil lead
• Extremely high melting point (3652*C)
• Used in sporting goods and aircraft.
3. Fullerenes are dark-colored solids made of
spherically networked carbon-atom cages.
Fullerenes
• Discovered in the mid-1980’s
• Are part of soot that forms
when carbon-containing
materials are burned with
limited oxygen
• Most stable form is C60
• Because of its structural resemblance to
geodesic domes…they names C60
“Buckminsterfullerene” in honor of geodesic
dome architect, Buckminster Fuller.
• Resembles a soccer ball called “Buckyball”
Chapter 20.2
• Organic compounds are covalently bonded
compounds containing carbon, excluding
carbonates and oxides.
• The diversity of organic compounds
results from the uniqueness of carbon’s
structure and bonding.
• Carbon’s electronic structure allows it to
bind to itself and form chains and rings,
to bind covalently to other elements, and
to bind to itself and other elements in
different arrangements.
• Catenation the covalent binding of an
element to itself to form chains or rings.
• Hydrocarbons are the simplest organic
compounds, composed of only carbon and
hydrogen.
• Structural Formula indicates the number and
types of atoms present in a molecule and also
shows the bonding arrangement of the
atoms.
CH3-CH2-CH3
Condensed formula
• Isomers are compounds that have
the molecular formula but different
structures.
• Structural isomer are isomers in
which the atoms are bonded together
in different orders
2-methylpropane
• Geometric isomers are isomers in which the
order of atom bonding is the same but the
arrangement of atom in space is different.
• Cis groups on the same side
• Trans groups are on opposite side (Cl)
H
Cl
Cis
Trans
Chapter 20.3
• Saturated hydrocarbons are hydrocarbons in
which each carbon atom in the molecule
forms four single covalent bonds with other
atoms.
• Alkanes are hydrocarbons that contain only
single bonds. (No Double Bonds). Formula
CnH2n+2
For every Carbon
4 hydrogens
• Cycloalkanes are alkane in which the
carbon atoms are arranged in a ring,
or cyclic structure. Formula CnH2(n)
C5H2(5) = C5H10
Cyclopentane
• Table 20-3 You need to memorize!!!
Pg 636
• Alkyl groups are groups of atoms
that are formed when one hydrogen
atom is removed from an alkane
molecule.
• Alkyl groups are named by replacing
the suffix –ane of the parent alkane
with the suffix -yl
Rules for Alkane Nomenclature
1. Name the parent hydrocarbon. Find the
longest continuous chain of carbons. Add
the suffix –ane to the prefix.
7 carbons is
the longest
chain.
So the
parent name
is heptane
2. Add the names of the alkyl groups. Add
the names in front of the parent name
in alpha order. If more than one group
has the same name add di-, tri-,tetra….
ethly methyl heptane
ethyl
methyl
3. Number the carbon atoms in the parent
hydrocarbon. IF one or more alkyl groups are
present, number the carbon atoms in the
continuous chain so that the alkyl groups have the
lowest position #’s. If there are 2 equal lowest
position numbers with 2 different alkyl groups,
give the lowest number to the alpha order.
4. Insert position numbers. Put the position
#’s of each alkyl group in from of the
name of that alkyl group.
5. Punctuate the name. #’s from name
hyphen.If there is more than 1 #...put
commas in between #’s.
3-ethyl-2-methyl heptane
Examples
1.
Sample problems in text pgs.
639-641
 Them OUT
2.
Rules for Cycloalkane
Nomenclature
1. Name the parent hydrocarbon. Count the #
of carbons in the ring. Add the prefix
cyclo-. Add the suffix –ane to the prefix.
6 carbons so cyclohexane
2. Add the names of the alkyl groups. If
more than one of the same alkyl group is
present use di-, tri-, tetra-…
methyl
methyl
methyl methyl cyclohexane
Dimethyl
3. Number the carbon atoms in the parent
hydrocarbon. IF one or more alkyl groups are
present, number the carbon atoms in the ring so
that the alkyl group that comes 1st alphabetically
has #1. Then, # in the direction that gives the
rest of the alkyl groups the lowest numbers
possible.
1
1
1
2
4. Insert position numbers.
5. Punctuate the name.
1,2-dimethylcyclohexane
• 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. Contain from 1 to
more than 50 carbon atoms.
• Octane rating of a fuel is a measure of
its burning efficiency and its antiknock
properties.
Chapter 20.4
• Unsaturated hydrocarbons are
hydrocarbons in which not all carbon
atoms have four single covalent
bonds. (Double and triple bonds).
• Alkenes are
hydrocarbons
that contain
double covalent
bonds.
Rules for Alkene Nomenclature
1. Name the parent hydrocarbon. Locate the
longest continuous chain that contains the
double bond(s). If there is only one double
bond, add the suffix –ene to the prefix. If
there is more than one double bond, modify
the suffix to indicate the number of double
bonds. 2=adiene, 3=atriene…
4 carbons 1
double bond
Butene
Methyl
Methyl
2. Add the names of the alkyl groups.
•
Dimethylbutene
3. Number the carbon
atoms in the parent
hydrocarbon. Number
the chain so that the 1st
carbon in the double
bond has the lowest
number. IF numbering
from both ends gives
equivalent positions for
two double bonds, then
number from the end
nearest the first alkyl
group.
4. Insert position
numbers. Place
double-bond position
numbers immediately
before the name of
the parent
hydrocarbon alkene.
• Place alkyl group
position numbers
immediately before
the mane of the
corresponding alkyl
group.
5. Punctuate the name.
• Alkynes are hydrocarbons with triple
covalent bonds.
Propyne
1.
2.
3.
4.
5.
Rules for naming Alkynes
Name the parent hydrocarbon. Locate the longest
continuous chain that contains the Triple bond(s). If there
is only one triple bond, add the suffix –yne to the prefix.
If there is more than one triple bond, modify the suffix
to indicate the number of double bonds. 2=adiyne,
3=atriyne…
Add the names of the alkyl groups
Number the carbon atoms in the parent hydrocarbon.
Number the carbon atoms in the chain so that the 1st
carbon atom in the triple bond nearest the end of the
chain has the lowest number. If numbering from both ends
gives the same positions for two triple bonds, then number
from the end nearest the 1st alkyl group.
Insert position numbers.
Punctuate the name.
• Aromatic hydrocarbons are
hydrocarbons with six-membered
carbon rings and delocalized
electrons.
• Benzene is the primary aromatic
hydrocarbon.
Benzene
Aromatic Hydrocarbon
Nomenclature
1. Name the parent hydrocarbon. The parent
hydrocarbon is the benzene ring.
2. Add the names of alkyl groups.
3. Number the carbon atoms in the parent
hydrocarbon. If there are 2 or more alkyl groups
attached to the benzene ring, number the carbon
atoms in the ring. Assign position number one to
the alkyl group that comes 1st alpha. Then number
in the direction that gives the rest of the alkyl
groups the lowest #’s.
4. Insert position numbers.
5. Punctuate the name.
Functional Groups
• Halogens- end in o• 1-Chloropentane Cl-C-C-C-C-C
• Alcohol end in –nol
• Pentanol
C-C-C-C-C-OH
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Work Cited
Cartoon. Aug. 11, 2006. http://www.nearingzero.net/sbunch5.html
“Buckyball”. May 10, 2007.
http://www.ydae.purdue.edu/ANE/images/colorBuckyball.jpg
“Butane”. May 11, 2007.
http://www.purchon.com/chemistry/images/butane.gif
“2-methylpropane”. May 11, 2007. http://www.chemistry-help.info/2methylpropane.gif
“1,2-dichloroethane trans”. May 11, 2007.
http://content.answers.com/main/content/wp/encommons/thumb/5/5d/150px-1,2-dichloroethane.png
“Cyclopentane”. May 11, 2007.
http://www.chemvc.com/~tim/cyclopentane.j
pg
• “Prefix chart”. May 11, 2007.
•
http://www.schoolisland.com/review/reference/chem%20table%20p.gi
f
“Propane”. May 13, 2007.
http://ibchem.com/IB/ibfiles/organic/org_img/propane.gif
• “Methane, Ethane, Propane”. May 13, 2007.
http://cache.eb.com/eb/image?id=16894
• Cyclohexane”. May 13, 2007.
http://www.elmhurst.edu/~chm/vchembook/image
s/515cyclopentane.GIF
• “Ethene, Butene, Propene, Pentene”. May 14, 2007.
http://www2.milwaukee.k12.wi.us/madison/dept01
/science/kdog/notes/alkenes.gif
• “Propyne”. May 14, 2007.
http://hyperphysics.phyastr.gsu.edu/hbase/organic/imgorg/propyn
e.gif
• “Benzene”. May 14, 2007.
http://www.amacad.org/images/benzene.gif