Organic Chemistry

1

• Organic Chemistry
• The study of carbon based compounds with some
  exceptions.
• The exceptions are carbides, carbonates and
  oxides.

2
Why is the carbon atom unique?

• Carbon is unique
• 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.

3
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.

4
Petroleum

• Petroleum is a mixture of alkanes, cycloalkanes,
  and aromatic hydrocarbons.
• 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.
• Here it forms an accumulation of petroleum and
  saturates the porous rock creating an oil field.

5

• Refinery and tank storage facilities, like this
  one in Texas, are needed to change the
  hydrocarbons of crude oil to many different
  petroleum products.

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Hydrocarbons

• Hydrocarbons exist in three general shapes.
• Aliphatic- in chains

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Hydrocarbons

• Cyclic- in rings

8
Hydrocarbons

• Aromatic contain the benzene ring. They usually
  have distinctive odors.

9
Hydrocarbons

• Hydrocarbons are also distinguished by the type
  of bonds they contain between the carbon atoms.

10
Hydrocarbons based on bond type

• 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.

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Alkanes, Alkenes, and Alkynes
Carbon requires an octet. Carbon must have 4
bonds around it.
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Alkane Nomenclature

• 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

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Alkane Nomenclature

• 5 pentane C5H12
• 6 hexane C6H14
• 7 heptane C7H16
• 8 octane C8H18
• 9 nonane C9H20
• 10 decane C10H22

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Alkane Nomenclature

• 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.

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Alkane practice

• 2 ethane C2H6
• 3 propane C3H8
• 4 butane C4H10

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Using the condensed method

• 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.

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Alkenes

• 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.

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Alkenes that contain more than 3 carbon atoms

• 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
• H2CCH-CH2-CH3 1-butene
• H3C-CHCH-CH3 2-butene

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Determining the location of the double bond

• Carbon atoms are numbered by starting with the
  carbon atom closest to the double bond. The
  numbering can start from either side.
• H2CCH-CH2-CH3 1-butene
• 1 2 3 4

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Determining the location of the double bond

• H3C-CH2-CHCH2 1-butene C4H8
• 4 3 2 1
• Write molecular and structural formulas for
• 1-pentene
• 2-pentene
• 3-hexene

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Alkynes

• 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.

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Alkynes

• 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.

23
Review of part I of an introduction to Organic
chemistry

• Write molecular and structural formulas for the
  following (you may use the traditional or
  condensed structural formulas).
• Methane
• Propane
• Ethene
• 1-Butene
• 2-Hexene
• 3-Octene
• Ethyne
• 2-Heptyne
• 3-Octyne

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Hydrocarbon Radicals

• 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_______________

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Functional Groups

• 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.

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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.

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Saturated and Unsaturated Hydrocarbons

• 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.

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Key terms from part II.

• 1. Hydrocarbon radical
• 2. Functional group
• 3. Alcohol
• 4. Saturated hydrocarbon
• 5. Unsaturated hydrocarbon

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Inorganic and Organic nomenclature practice

• Write the missing name or molecular formula
  for the following.
• Sulfur dioxide
• Carbon dioxide
• Phosphorus pentachloride
• Dinitrogen tetroxide
• Sulfur trioxide
• H3C-CH2-OH
• H3C-CH2-CH2-CH3
• H3C-CHCH-CH2-CH3
• 2-Hexyne
• Butyl alcohol
• Methanol
• Hydrosulfuric acid
• Sulfuric acid
• Sulfurous acid
• Hypochlorous acid

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Inorganic and Organic nomenclature practice

1. Oxygen difluoride
2. Hydrochloric acid
3. Ethyne
4. 2-Hexene
5. Propyl alcohol
6. HCN(aq)
7. ethene
8. HNO2(aq)
9. Carbonic acid
10. Acetic acid
11. Carbon tetrachloride
12. Propane
13. Propene
14. propyne