Transcript organic chemistry - Madison County Schools

Organic
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Chemistry
The study of carbon based compounds with some
exceptions.
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The exceptions are carbides, carbonates and oxides.
Why is the carbon atom unique?
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Carbon is unique
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It has 4 electrons in its outer shell.
It has room for 4 bonds to 4 other atoms.
These bonds can be single, double, or triple.
Hydrocarbons
 The
largest group of organic
compounds are known as
hydrocarbons. These compounds
contain hydrogen and carbon. Most of
these compounds are derived from
petroleum.
Petroleum
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Petroleum is a mixture of alkanes, cycloalkanes,
and aromatic hydrocarbons.
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Petroleum is formed from the slow decomposition of
buried marine life, primarily plankton and algae.
As petroleum is formed it is forced through
porous rock until it reaches an impervious layer
of rock.
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Here it forms an accumulation of petroleum and
saturates the porous rock creating an oil field.
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Refinery and tank storage facilities, like this one in Texas, are needed to
change the hydrocarbons of crude oil to many different petroleum
products.
Hydrocarbons
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Hydrocarbons exist in three general
shapes.
Aliphatic- in chains
Hydrocarbons
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Cyclic- in rings
Hydrocarbons
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Aromatic – contain the benzene ring. They
usually have distinctive odors.
Hydrocarbons
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Hydrocarbons are also distinguished by the
type of bonds they contain between the
carbon atoms.
Hydrocarbons based on bond type
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Alkanes – contain only single covalent
bonds between carbon atoms.
Alkenes – contain at least one double bond
between carbon atoms.
Alkynes – contain at least one triple bond
between carbon atoms.
Alkanes, Alkenes, and Alkynes
Carbon
requires an
octet. Carbon
must have 4
bonds around
it.
Alkane Nomenclature
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When writing the names for alkanes,
prefixes must be known. The prefixes
identify the number of carbon atoms in the
compound.
1 methane CH4
2 ethane C2H6
3 propane C3H8
4 butane C4H10
Alkane Nomenclature
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5 pentane C5H12
6 hexane C6H14
7 heptane C7H16
8 octane C8H18
9 nonane C9H20
10 decane C10H22
Alkane Nomenclature
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When writing formulas for the alkanes we
use the formula CnH2n + 2
n represents the number of carbon atoms
Example: methane contains 1 carbon atom.
C1H2 X 1 + 2
CH4
Without looking back at the prefixes write
the molecular and structural formulas for
ethane – butane.
Alkane practice
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2 ethane C2H6
3 propane C3H8
4 butane C4H10
Using the condensed method
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In the condensed form of a structural formula,
carbon atoms are still written separately.
However, the hydrogen atoms that are attached to
a carbon atom are grouped with that carbon atom.
Example: pentane C5H12
H3C-CH2-CH2-CH2-CH3
Write the molecular, traditional structural, and
condensed structural formulas for octane.
Alkenes
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Alkenes must contain at least one double
bond. They take the general form of CnH2n.
The first Alkene is ethene. C2H4
Write the molecular formula and the
structural formula for propene.
Alkenes that contain more than 3
carbon atoms
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When writing the names for alkenes that
contain more than 3 carbon atoms the
location of the double bond must be
included.
Example: Butene can be 1-butene or
2-butene. C4H8
H2C=CH-CH2-CH3 1-butene
H3C-CH=CH-CH3 2-butene
Determining the location of the double
bond
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Carbon atoms are numbered by starting
with the carbon atom closest to the double
bond. The numbering can start from either
side.
H2C=CH-CH2-CH3 1-butene
1 2 3
4
Determining the location of the double
bond
H3C-CH2-CH=CH2 1-butene C4H8
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4 3 2
1
 Write molecular and structural formulas for
1-pentene
2-pentene
3-hexene
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Alkynes
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Alkynes must contain at least one triple
covalent bond. They take the general form
of CnH2n-2. The first alkyne is ethyne.
Ethyne C2H2 is also known as acetylene,
which is used as the gas for welding.
Alkynes
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Alkynes use the same nomenclature as the
Alkenes. After propyne the location of the
triple bond must be identified.
Write molecular and structural formulas for
propyne, 2-butyne, 1-pentyne, and
3-heptyne.
Review of part I of an introduction to
Organic chemistry
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Write molecular and structural formulas for the
following (you may use the traditional or
condensed structural formulas).
1.
Methane
Propane
Ethene
1-Butene
2-Hexene
3-Octene
Ethyne
2-Heptyne
3-Octyne
2.
3.
4.
5.
6.
7.
8.
9.
Hydrocarbon Radicals
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If one of the hydrogen atoms together with
its associated electron is removed from a
hydrocarbon molecule a radical is formed.
Examples:
Methane CH4 becomes Methyl CH3
Ethane C2H6 becomes Ethyl C2H5
Propane C3H8 becomes_______________
Functional Groups
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A group of atoms that give characteristics
and properties to organic compounds.
These functional groups may be aldehydes,
alcohols, ethers, ketones, amino acids,
amides, and others. We will study the
alcohols because of their wide use in
combustion reactions.
Alcohols
Alcohols contain the hydroxyl group OH. Unlike the
hydroxide ion the hydroxyl group does not contain an
electrical charge.
Simple alcohols take the general form R - OH.
The R represents a hydrocarbon radical.
Symbol R An atom or a group of atoms with at least one
unpaired electron.
Example: If the radical is methyl (CH3), the
alcohol becomes CH3OH which is known as methyl
alcohol or methanol.
Write the molecular formulas for propyl alcohol and
butanol.
Saturated and Unsaturated Hydrocarbons
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Saturated hydrocarbons contain the
maximum number of hydrogen atoms
around each carbon atom. They contain
only single covalent bonds between carbon
atoms, therefore they are usually alkanes.
Unsaturated hydrocarbons are just the
opposite and they contain double or triple
bonds between carbon atoms. They are
usually alkenes and alkynes.
Key terms from part II.
1. Hydrocarbon radical
2. Functional group
3. Alcohol
4. Saturated hydrocarbon
5. Unsaturated hydrocarbon
Inorganic and Organic nomenclature
practice
Write the missing name or molecular formula for the following.
1.
Sulfur dioxide
2.
Carbon dioxide
3.
Phosphorus pentachloride
4.
Dinitrogen tetroxide
5.
Sulfur trioxide
6.
H3C-CH2-OH
7.
H3C-CH2-CH2-CH3
8.
H3C-CH=CH-CH2-CH3
9.
2-Hexyne
10.
Butyl alcohol
11.
Methanol
12.
Hydrosulfuric acid
13.
Sulfuric acid
14.
Sulfurous acid
15.
Hypochlorous acid
Inorganic and Organic nomenclature
practice
1.
2.
3.
4.
5.
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7.
8.
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10.
11.
12.
13.
14.
Oxygen difluoride
Hydrochloric acid
Ethyne
2-Hexene
Propyl alcohol
HCN(aq)
ethene
HNO2(aq)
Carbonic acid
Acetic acid
Carbon tetrachloride
Propane
Propene
propyne