Alkanes review

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					Alkanes review
 Organic Chemistry
    Chapter 12
                          12.1
• Where did the term organic come from?
      • Living organism
• Today the definition of organic is
      • The study of hydrocarbons and their derivatives
• Why are there more Organic compounds than
  inorganic compounds?
      • Carbons ability to bond with itself (Isomers)
• The idea a supreme being was needed to creat
  organic compounds was called the ____ theory
      • Vital force
• Who is credited with proving the vital force theory
  incorrect?
      • Fredrick Wohler
                      12.2
• Outside electrons are called ________ electrons
      • Valence
• Carbon has _______ valence electrons
      •4
• Carbon has to have _____ covalent bonds
      •4
• The relative attraction that an atom has for the
  shared electrons in a bond is called ______
      • Electronegativity
• A bond made by sharing electron is called a
  _______ bond
      • covalent
• Alkanes are also called _______which is derived
  from a Latin word meaning "little activity", and
  means that the compounds are very unreactive.
      • PARAFFINS
                         12.3
• What is a hydrocarbon?
      • Compounds that contain ONLY hydrogen and
        carbon.
• What is a hydrocarbon derivative
      • Compouond that contains hydrogen and carbon and
        one or more additional elements such as O,N,S,P,F,Cl
• What is a saturated Hydrocarbon?
      • Hydrocarbon in which all the carbon – carbon bonds
        are single bonds. There is no room for anything else.
• What is an unsaturated hydrocarbon?
      • A hydrocarbon that contains one or more carbon –
        carbon multiple bonds: double, triple bonds or both
                    12.4
• A saturated hydrocarbon in which the carbon atom
  arrangement is acyclic belongs to what organic
  class?
      • Alkane
• The general formula for Alkanes is
      • CnH2n+2 (n is the number of carbon atoms)
• In alkanes the geometric shape formed around the
  carbon is a(n) _____
      • tetrahedron
Summary of classification terms for organic compounds


                        Organic
                       compounds

        Hydrocarbons               Hydrocarbon
                                    Derivatives


    Saturated           Saturated
   Hydrocarbons        Hydrocarbons
                      12.5
• Chemical formulas give what information
      • What is involved and how much of it
      • H2O has 2 Hydrogen and 1 Oxygen
• Structural formulas give what information?
      • What is invoved, how much of it and how it
        is arranged.
      • CH3CH(CH3)CH2CH2CH3


               C-C-C-C-C
                 C
                    12.5
                                H H H H H
Expanded Structural formula
                               H C-C-C-C-C H
                                 H H H H H
Condensed structural formula
          CH3CH2CH2CH2CH3

Ultra condensed structural formula
             CH3(CH2)3CH3
 Skeletal structural formula
               C-C-C-C-C
                       12.6
• _________ are compounds with the same
  molecular formula but different structural
  formula’s
      • Structural Isomers
• Continuous chain isomer
      • Straight chain or normal chain
• Branched chain isomer
                      12.7
• Differing orientations of a molecule made possible
  by rotations about single bonds are called _____
      • Conformations
• eclipsed conformation

•staggered conformation
                    Isomers
• Positional Isomer
     • Change in position of a least one non-hydrogen or
       carbon atom
                         12.8
• IUPAC stands for _________
      • International Union of Pure and Applied
        Chemistry
• An atom or group of atoms attached to a chain (or ring)
  of carbon atoms is called a(n)
      • Substituent
• The group of atoms that would be obtained by removing
  a hydrogen atom from an alkane are called ____
      • Alkyl group
     Nomenclature of Alkanes
• Step 1: Longest continuous chain
     • (parent chain)
• Step 2: Number chain
     • (lowest number to substituants)
• Step 3: Identify substituants
     • (name and location)
• Step 4: If more than one identical
  substituant add appropriate prefix
     • Di, tri, tetra
• Step 5: Alphabetical order for substituants
• Step 6: correct punctuation
  Nomenclature of Alkanes
(CH3)2CHCH2CH(C2H5)CH2CH3


  1
  C
    C C C C C
  C     CC
4 ethyl 2 methyl hexane
                    12.9

• Classification of carbon atoms

       primary 1°        secondary 2º
                C
          C-C-C-C-C-C-C
              CC
     tertiary 3º        quaternary 4º
                  12.10
• Branched – Chain Alkyl groups
                            CH CH3
CH CH3                      CH2
CH3                         CH3
      Isopropyl        Teriary-butyl group


CH2                   CH3 C CH3
CH CH3
CH3 Isobutyl group            CH3
                       Secondary –butyl group
                      12.11
• A saturated hydrocarbon in which the
  carbon atoms are connected to one another
  in a cyclic (ring) arrangement belongs to
  what organic class?
     • Cycloalkanes
• The general formula for cycloalkanes is
     • CnH2n
                12.12
• Naming cycloalkanes
          12.13
• conformations
     • Boat
     • Chair
• Cis-trans
     • Are compounds that have the same molecular and
       structural formulas but different arrangements of
       atoms in space because of restricted rotation around
       bonds
     • CIS
     • TRANS
                  12.14
• Sources of Alkanes and cycloalkanes
• Natural gas and petroleum (oil) make up
  the largest and most important sources.
• Crude petroleum is a complex mixture of
  hydrocarbons that can be separated in to
  useful fractions through refining
                        12.15
• Physical Properties
     •   Insoluble in water
     •   Less dense than water
     •   Boiling points increase with chain length
     •   Branching lowers the boiling point
     •   Cycloalkanes have higher boiling points than their
         noncyclic counterparts
• Physical state
     • 1 - 4 carbons = gas @ room temperature
     • 5 – 17 carbons = liquid @ room temperature
     • 18+ = Solids @ room temperature
                         12.16
• Combustion
     • CO2 and H2O
• Halogenation
     • Substitution reaction
     • Flurorination, chlorination, bromination, iodination
     • Stepwise reaction
     • CH4 + Cl2      CH3Cl + HCl
     • CH3Cl + Cl2    CH2Cl2 + HCl
     • CH2Cl2 + Cl2   CHCl3 + HCl
     • CHCl3 + Cl2     CCl4   + HCl
     • During reaction toxicity increases flammability
       decreases
12.17
                               At a Glance
                         Alkanes and Cycloalkanes


  Physical Properties                                          Chemical Properties


Solubility          Density           Boiling points              Combustion         Halogenation
•Insoluable in      •Liquids and      •Increase as carbon         •All Alkanes and   •Hydrogen atoms are
water               solids are less   chain length increases      cycloalkanes are   replaced with halogen
                    dense than                                    flammable          atoms (a subatitution
•Soluable in                          •Decrease with
                    water                                                            reaction)
nonpolar solvents                     increase in degree of       •Combustion
                    •Float on top     branching                   products are CO2   •Requires the presence
                    of water                                      and H2O            of heat or light