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Unit 15 Notes and ICP’s
Organic Chemistry for AP
Hydrocarbons
 Hydrocarbons are compounds consisting of hydrogen and carbon.
 Carbon always forms four bonds and in singly bonded compounds is sp3 hybridized with bond angles of
109.5˚
 Hydrocarbons are non polar. Some organic compounds can be more polar if they contain functional
groups to make them so [ie….-OH (alcohols), -NH2(amines), etc.]
 Saturated hydrocarbons – only contain single C-C bonds
 Unsaturated hydrocarbons – contain multiple double or triple C-C bonds
Alkanes
Alkanes only contain single bonds (sigma bonding) and have the general formula CnH2n+2.
The prefixes for alkenes that you need to know in combination with the suffix –ANE are listed for below:
1-carbon
methane
5-carbons
pentane
9-carbons
nonane
2-carbons
ethane
6-carbons
hexane
10-carbons
decane
3-carbons
propane
7-carbons
heptane
4-carbons
butane
8-carbons
octane
Cycloalkanes
These hydrocarbons exist in ring structures with general formula CnH2n. There is considerable bond strain for 3
and 4 carbon rings. 5 and 6 carbon rings have much less bond strain. They can buckle their structures to
achieve more stability. You name them just as alkanes but add the prefix CYCLOAlkenes
These are compounds containing at least one carbon to carbon double bond with the general formula CnH2n.
They use the same prefixes as alkanes but end in an –ENE suffix. Alkenes are much more reactive than their
alkane counterparts because of their double bonds (1 sigma and 1 pi). The pi bond creates a ridged framework
with sp2 hybridization.
Alkynes
These are compounds containing at least one carbon to carbon triple bond with the general formula CnH2n-2.
They use the same prefixes as alkenes but end in a –YNE suffix. Alkynes are VERY reactive and have sp
hybridization.
Nomenclature of Alkanes, Alkenes, and Alkynes:
1. Use generic prefix according to the number of carbons then add the correct suffix.
2. Select the longest continuous carbon chain to dictate the number of carbons for the correct prefix “parent
chain”.
3. Any branch off of the parent chain is called a substituent group and it is named according to the number
of carbon atoms it contains with a “-yl” ending rather than “-ane”.
4. Specify the position of the branch on the parent by putting a number in front with the lowest #s possible.
5. For multiple substituents that are identical, use di-, tri-, tetra- etc, and repeat the numbers.
6. Numbers are separated by commas and from letters by dashes (1,1-dichloroethane).
7. Arrange substituents by name, alphabetically, regardless of numbers or complexity.
8. For alkenes and alkynes put a number right before the parent chain name, specifying position of the
double or triple bond. Select numbering which always gives the lowest value.
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AP Chemistry
Structural Isomerism
This occurs when molecules have the same molecular formula but have different structural formulas
Ex) C5H12
CH3
H3C
pentane H3C
CH3
methylbutane
CH3
CH3
H3C
CH3
CH3
dimethylpropane
Positional Isomers
In position isomers, structures have the same molecular formula with the same functional group located in a
different position. Positional isomers also include differing locations of double and triple bonds in a given
compound.
Ex) C3H7OH
H3C
CH3
OH
OH
2-propanol
1-propanol
H3C
Geometric Isomers (Stereoisomers)
Geometric isomers also have the same molecular formula and arise because there are 2 ways that substituents
can be positioned when attached to a carbon to carbon double or triple bond. When substituents are positioned
on the same side of the double bond the isomer has the prefix “cis”. When substituents are positioned on the
opposite side of the double bond it has the prefix “trans”.
H
cis-2-butene
H3C
H3C
H
CH3
H
H
trans-2-butene
CH3
Functional Groups
Hydrocarbons and substituted products are organized and classified by their “functional groups”. They may be
substituted for either hydrogen atoms or carbon atoms in compounds. The rest of the molecule is symbolized
by “R-“. Some common functional groups are:
Alcohols
R
Amines
R
OH
O
(hydroxyl group)
Ketones
R
NH2
R'
O
(carbonyl group)
OH
O
(-COOH)
R
Organic acids
O
Ethers
R
R
R'
H (terminal carbonyl, -CHO)
Aldehydes
O
X
Alkyl halides
R
R'
Amides
O
R
NH
R
Esters
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O
R'
-NITRO group
2
-NO2 (substituent only)
AP Chemistry
Nomenclature of Functional Group Compounds
 Alcohols are names by the alkyl prefix + “-ol”
H3C
OH
Ex) ethanol

Ethers are named by listing substituents with a “-yl” ending + “ether”
Ex) diethyl ether H3C

O
CH3
Alkyl halides are named by the halogen root + “O” + parent name
H3C
Cl
Ex) chloroethane

Aldehydes are named by the alkyl prefix + “-al” ending
O
H3C
H
Ex) ethanal

Ketones are named by alkyl prefix + “-one” ending
H3C
O
Ex) propanone

CH3
Organic Acids are named by alkyl prefix + “-oic acid” ending
O
H3C
OH
Ex) ethanoic acid

Esters are named from the alcohol name with a “-yl” ending, then the acid name with an “-oate” ending
O
H3C
O
Ex) methyl ethanoate

CH3
Amines are named by listing substituents with “-yl” ending + “amine”
H3C
NH2
Ex) ethyl amine

Amides are named from the amine name with a “-yl” ending, then the acid name with an “amide”
ending
O
NH
CH3
Ex) methyl ethanamideCH3
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AP Chemistry
Aromatic Compounds
These are based on the benzene ring, C6H6. Aromatic compounds have a characteristic odor, and thus, the
name. When benzene reacts with other species, the substituents replace hydrogen atoms bonded on the carbon
ring. Position on the ring can be numbered clockwise with the highest priority substituent being on the number
1 carbon. When additional substituents are added, the 1,2- positions are called “ortho”, the 1,3-positions are
called “meta”, and the 1,4 positions are known as “para”:
Cl
Cl
Cl
ortho (o-)
meta (m-)
Cl
para (-p)
Cl
Cl
Common names for some aromatics are as follows:
NH2
CH3

Toluene (aka methyl benzene)

Xylene (dimethyl benzene)
and
Aniline
CH3
CH3
CH3
ortho-xylene

CH3
meta- xylene
CH3
para-xylene
H3C
As a functional group benzene is known as a “phenyl” group
ex)
diphenylmethanol
OH
General Types of Organic Reactions
I.
Reactions of Alkanes
 Substitution Reaction
One or more H atoms is substituted; Light catalyzed; Mix of products
H
H
H
H
H
H
+
Cl
Cl
hυ
H
+
HCl
+
dichloromethane
2 HCl
Cl
Methane
chloromethane
H
H
H
H
H
H
+
2 Cl
Cl
hυ
Methane
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Cl
Cl
AP Chemistry
II.
Reactions of Alkenes and Alkynes
 Addition Reactions
Reagents add across the double or triple bonds; need appropriate catalyst.
TYPE I – Symmetrical Reagent Added to a Hydrocarbon
a. Hydrogenation: addition of H2 (duh!!)
Alkene
H3C
CH2
+
H
H
Pt
Propene
CH3
H3C
propane
Alkyne
H3C
CH3 + 2 H
H
H3C
CH3
Pt
2-butyne
butane
b. Halogenation: addition of X2
Alkene
Cl
H3C
CH2
+
Cl
Cl
Pt
Propene
Cl
H3C
1,2-dichloropropane
Alkyne
H3C
CH
Cl
Cl
Cl
Cl
H3C
+ 2 Cl
Cl
propyne
Pt
1,1,2,2-tetrachloropropane
*Reverse reactions are possible – called dehydration AND dehalogenation*
TYPE II – Asymmetrical Reagent Added to a Hydrocarbon
(Makovnikov’s Rule: When asymmetrical reagent (HX) is added, the H goes to carbon with the larger number
of H’s and X joins the carbon with fewer numbers of H’s)
a. Hydrohalogenation
Alkene
H3C
H3C
CH2
+
HBr
Propene
H
Br
2-bromopropane
Alkyne
Br H
H3C
CH
H3C
+ 2 HBr
propyne
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H
Br H
2,2-dibromopropane
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AP Chemistry
b. Hydration
CH3
H3C
CH2
H3C
+
H OH
OH
Propene
III.
2-propanol (NOT 1-propanol)
Halogenation of Benzene
Br
+
Br
Br
FeBr3
Benzene
IV.
bromobenzene
Esterification
O
H
H
+
methanol
V.
H3C
O
CH3
H
OH
CH3
O
HO
ethanoic acid
methyl ethanoate
water
Hydrolysis (reverse of esterification)
H3C
O
H3C
O
OH
O
O
H3C
O
O
H3C
+ H2O
H3C
OH
Fat (ester made between glycerol and 3 fatty acids)
+
fatty acids
O
O
Na
O
R
O
+
O
O
Na
O
R
O
R
Fat
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+
O
O
O
+
Na
3 Na OH
R
lye
O
soap
6
O
H
O
H
O
glycerol
Saponification – soap production resulting from the reaction of a fat with NaOH (lye)
VI.
H
OH
O
H3C
O
R
H OH
+
O
R
HBr
+
H
O
H
O
H
O
+
+
glycerol
AP Chemistry
Basic Organic Nomenclature Practice
Name the following compounds:
H3C
CH3
H3C
CH3
CH3
H3C
CH3
H3C
H3C
CH3
CH3
CH3
CH3
CH3
H3C
H3C
H
CH3
H3C
CH3
H3C
H3C
H
HC
H
CH3
CH
H3C
H
CH3
H3C
CH3
CH2
CH3
H3C
H3C
CH3
CH3
CH3
CH3
H3C
CH3
CH3
CH3
H3C
CH3
CH3
CH3
CH3
CH3
H3C
H3C
CH3
CH3
CH3
CH3
CH3
H3C
CH3
CH3
CH3
CH3
CH3
H3C
CH3
CH3
CH3
H3C
CH3
CH3
H3C
CH3
CH3
CH3
H3C
Br
Cl
CH3
CH3
H3C
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CH3
CH3
CH3
CH3
CH3
H3C
H3C
CH3
H3C
H2C
CH3
H3C
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AP Chemistry
CH3
Write the structures for the three isomeric saturated hydrocarbons having the molecular formula C5H12.
Write the structures for the five isomeric saturated hydrocarbons having the molecular formula C6H14.
Draw structures for cis and trans isomers of 1,2-dichloroethene.
Draw the structure for the following:
2,2-dimethylpropane
1,3-pentadiene
3-hexyne
3,3-dimethylcyclobutene
3,4-diethylhexane
Draw and rename the following compounds. They are named incorrectly.
1-methyl-2-butylpentane
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3,5-diethylhexane
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AP Chemistry
Advanced Organic Nomenclature Practice
CH3
H3C
H3C
OH
H3C
H3C
OH
OH
CH3
CH3
HO
CH3
O
O
CH3
H3C
CH3
OH
H3C
NH
CH3
CH3
H3C
H2N
O
H3C
NH2
CH3
O
CH3
H3C
CH3
H3C
O
H3C
CH3
O
CH3
O
N
O
NO 2
H3C
O
O
H3C
O
Br
H
H
OH
O
Br
H3C
H3C
H3C
N
OH
OH
H3C
CH3
NO 2
CH3
Br
CH2
O
Br
H3C
Cl
Br
Br
Br
NH2
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AP Chemistry
Basic Organic Reaction Practice
1. ethane and chlorine
2. 2-butene and hydrogen
3. ethyne and 1 mole hydrogen
4. ethyne and 2 moles hydrogen
5. 2-butene and bromine
6. 2-methyl-2-butene and water
7. 2-methyl-2-butene and hydrogen chloride
8. phenyl methanoate and sodium hydroxide
9. ethanoic acid and butanol
10. dimethyl amine and hydrochloric acid
O
11.
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H3C
Cl
and dimethyl amine
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AP Chemistry