Transcript Hydrocarbons and Fuels

Naming Isomers
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Organic Chemistry
Originally, chemical compounds were divided into 2 classes:
Inorganic or Organic
Organic compounds were derived from living things. It
was believed that they contained a ‘vital force’ and could
not be made from inorganic compounds (non-living sources).
Carbon has the ability to CATENATE, forming
covalent bonds with its own atoms. This allows for the
formation of many millions of carbon compounds
H
C
C
H
Ethene, C2H4
Organic Chemistry
Organic chemistry is basically the study of compounds
containing carbon (with the exclusion of oxides and
carbonates).
There are so many compounds containing carbon that a
whole branch of chemistry is devoted to their study.
Organic molecules may be
as simple as methane, CH4
or as complicated as
cholesterol
HO
Homologous series
A homologous series are a family of organic compounds with
the same general formula. They have a common
functional group.
Examples of homologous groups include:
Homologous
series
General formula Functional
group
Alkanes
CnH2n + 2
Alkenes
CnH2n
C=C
Alkynes
CnH2n - 2
C=C
Alkanols
CnH2n + 1 OH
R – OH
Alkanoic acids
CnH2n + 1 COOH
R – COOH
Alkanals
CnH2n + 1 CHO
R – CHO
Alkanes and Alkenes
Alkane general formula
C n H 2n+2
Alkene general formula
C n H 2n
Structural formula
H
H
H
H
C
C
C
H
H
H
H
Straight Chain
Name
H
H C H
H
H
H C C C
H
H
Meth
Eth
Prop
But
Pent
Hex
Hept
Oct
No C’s
1
2
3
4
5
6
7
8
Branched chains and
unsaturated C=C bond
CH3CH2CH3
CH3 (CH2)2CH3
CH3CH2CH2CH3
Condensed formula
Molecular formula C4H9
Naming Compounds of Carbon
Alkanes
1.
2.
3.
4.
5.
Identify the longest chain
Identify the ‘branches’ and name them.
Number the carbon atoms on the longest chain, at the end giving
the lowest numbers for the branches.
Write the branches in alphabetical order.
If there are more branches with the same name use di, tri etc
Alkenes
1.
2.
3.
4.
5.
Identify the longest chain, that contains a double bond.
Identify the ‘branches’ and name them.
Number the carbon atoms on the longest chain, starting from
the end nearest the double bond. Pick the lowest number to
describe the position of the double bond.
Write the branches in alphabetical order.
If there are more branches with the same name use di, tri etc
Naming Organic Compounds, Alkanes
H
H
H
H
H
H
H
CH3
C
C
C
C
C
C
C
H
CH2
H
H
H
CH2
H
1 CH3
H
CH2
10 CH3
1. Decide on the type of compound
(ie. consider functional group)
2. Select the longest chain.
3. Name the compound
with the branched chains
in alphabetical order.
alkane
10 C’s  decane
7-ethyl-3-methyldecane
H
H
C2H5 H
C
C
C
2
3
C = C
H
CH3
H
H
1. Decide on the type of compound
(ie. consider functional group)
1
CH3
H
alkene
2. Select the longest chain
7 C’s  heptene
3. Number the C atoms so that
the functional group has the
lowest number
hept-2-ene
4. Name the compound
with the branched chains
in ascending order.
5,5-dimethylhept-2-ene
H
H
CH3
H
H
H
C
C
C
C
C
H
CH3
Cl
H
H
1. Decide on the type of compound
(ie. consider functional group)
2. Select the longest chain
H
halogen (chloroalkane)
5 C’s  pentane
3. Name the compound
3-chloro-2,2-dimethylpentane
with the branched chains
and halogen in alphabetical order.
Structural Isomers
There are two types
1. Chain isomerism.
Here the isomers have different arrangements of carbon
atoms or different chains. For example there are two
compounds with the molecular formula C4H10
H
H
H
H
H
C
C
C
C
H
H
H
H
butane
H
H
H
H
H
C
C
C
H
CH3 H
H
2-methylpropane
Here, you can see that 2-methylpropane has a side chain.
2. Position Isomerism.
Here the isomers have the same carbon skeleton and
functional group but the position of the functional group
is different.
H H
H
H H H
H
C
C
C
H
H
Cl
H
1-chloropropane
H
H
H
H
C
C
C
H
H
OH
propan-1-ol
H
H
C
C
C
H
Cl
H
H
2-chloropropane
H
H
H
H
C
C
C
H
OH
H
propan-2-ol
H