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Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
Organic chem
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Organic chem

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  • 1. 10 Organic Chemistry Semester 1
  • 2. Introduction to Hydrocarbons
    • The study of carbon compounds is called organic chemistry.
    • The study of organic chemistry of biological systems is called biochemistry.
    • Most organic compounds consist of carbon and hydrogen, but may contain other elements such as oxygen, nitrogen or halogens.
    • Hydrocarbons are compounds with only C and H.
  • 3. Organic Chemistry and Hydrocarbons
    • Organic originally meant chemicals that came from organisms
    • Today, organic chemistry is the chemistry of virtually all compounds containing the element carbon
    • Over a million organic compounds, with a dazzling array of properties
  • 4. Introduction to Hydrocarbons
    • Hydrocarbon: a compound composed of only carbon and hydrogen
    H - C C - H H - C - C - H H H H H H C C H H H H y d r o c a r b o n s A l k a n e s A l k e n e s A l k y n e s A r e n e s O n l y c a r b o n - c a r b o n s i n g l e b o n d s O n e o r m o r e c a r b o n - c a r b o n d o u b l e b o n d s O n e o r m o r e c a r b o n - c a r b o n t r i p l e b o n d s O n e o r m o r e b e n z e n e - l i k e r i n g s E t h a n e E t h e n e ( E t h y l e n e ) E t h y n e ( A c e t y l e n e ) B e n z e n e
  • 5. Introduction to Hydrocarbons
    • Carbon has 4 valence electrons, thus forms 4 covalent bonds not only with other elements, but also forms bonds WITH OTHER CARBON ATOMS.
  • 6. Introduction to Hydrocarbons
    • Saturated compounds have only single bonds.
    • Unsaturated compounds have both single and double bonds/triple bonds.
    • Saturated means that no more H atoms can be added to the chain.
  • 7. Introduction to Hydrocarbons
  • 8.
    • Alkanes -
    • What they are
    • Structure
    • Naming
  • 9. What are they?
    • Alkanes : hydrocarbons containing only carbon-carbon single bonds
      • the first two alkanes are methane and ethane
  • 10. Alkanes
    • Physical Properties
      • Gases – liquids – solids
  • 11. Alkanes
    • Many alkanes are used for fuels:
      • methane, propane, butane, octane
    • As the number of carbons increases,
      • so does the boiling and melting pt.
    • The first 4 are gases;
      • Next ten are liquids;
      • higher alkanes are solids
  • 12. Structures of Alkanes
  • 13. Structure
    • Combined with the -ane ending is a prefix for the number of carbons
    • Homologous series-
      • In alkanes, it is: -CH 2 -
      • Alkanes can be straight chain or branched chain structures
  • 14. Structure
    • A straight chain looks like this:
    • Any smaller chain that takes the place of a hydrogen on a parent hydrocarbon is called, a substituent, or the branched part
    CH 3 – CH 2 – CH 2 – CH 2 – CH 3
  • 15. Showing structure
    • You can show structure in three ways:
    • a) the condensed structural formula
    • b) the full structure
    • c) the line-angle formula:
      • a line represents a carbon-carbon bond and an angle represents a carbon atom
      • a line ending in space represents a -CH 3 group
      • hydrogen atoms are not shown in line-angle formulas
    C H 3 C H 2 C H 2 C H 3 C H 3 C H 2 C H 3 C H 3 C H 2 C H 2 C H 2 C H 3 C H 3 C H 2 C H 2 C H 3 C H 3 C H 2 C H 3 C H 3 C H 2 C H 2 C H 2 C H 3 P e n t a n e B u t a n e P r o p a n e P e n t a n e B u t a n e P r o p a n e C o n d e n s e d s t r u c t u r a l f o r m u l a
  • 16. Naming
    • The name of the alkane varies according to the number of C atoms present in the chain.
  • 17. Naming Straight-Chain Alkanes
    • Names recommended by IUPAC (the International Union of Pure and Applied Chemistry)
        • end with -ane, the root part of the name indicates the # of carbons
    • We sometimes still rely on common names,
      • some of which are well-known
      • (ie polyethylene instead of polyethene)
      • (ie Acetic acid instead of ethanoic acid)
  • 18. Branched-Chain Alkanes
    • A hydrocarbon substituent is called an alkyl group .
      • use the same prefixes to indicate the number of carbons,
        • but the -ane ending is now -yl
        • methyl, ethyl, propyl, etc.
    • Gives much more variety to the organic compounds
  • 19. Branched-Chain Alkanes
    • 1. Count the number of Carbons in the main (parent) chain.
    • 2. Number so branches have low #
    • 3. Give position number to branch
    • 4. Prefix more than one branch (di, tri)
    • 5. Use proper punctuation ( - , )
    • longest chain is Heptane
    • side group is methyl
    • Position is #3 carbon
    • name is 3-methyl heptane
    • is an isomer of
    • octane C 8 H 18
  • 20. Branched-Chain Alkanes
    • From the name, draw the structure:
    • 1. Find the parent, with the -ane
    • 2. Number carbons on parent
    • 3. Identify substituent groups; attach
    • 4. Add remaining hydrogens
  • 21. Review of alkanes
    • What elements are present in an alkane
    • What is the prefix that means 4? 6? 1?
    • What types of alkane are there
    • Draw a) line angle, b) condensed structure c) structural formulae for
    • i)propane ii)3methyl octane iii) 2ethyl butane
    • For iii) what is this more correctly named as.
  • 22. Alkenes
    • Multiple bonds can also exist between the carbon atoms
    • Hydrocarbons containing carbon to carbon double bonds are called alkenes C=C C-C=C
    • Called “unsaturated” if they contain double or triple bonds
  • 23. Naming Alkenes
    • Find longest parent that has the double bond in it
    • New ending: -ene
    • Number the chain, so that the double bond gets the lower number
    • Name and number the substituents
  • 24. Alkynes
    • Hydrocarbons containing carbon to carbon triple bonds called alkynes
    • -C C-
    • Alkynes are not plentiful in nature
    • Simplest is ethyne- common name acetylene (fuel for torches)
  • 25. Questions
    • Draw a) line angle, b) condensed structure c) structural formulae for
    • 3 methyl pent-2-ene
    • 1 bromo 3 ethyl hexane
    • Hept-4-yne
    • 2,4 di methyl nonane
  • 26. Cyclic Hydrocarbons (not assessed)
    • The two ends of the carbon chain are attached in a ring in a cyclic hydrocarbon
      • named as “cyclo- ____”
    • hydrocarbon compounds that do NOT contain rings are known as;
      • aliphatic compounds
    • Rings less than 5 are unstable as the bonds are stressed and will tend to easily break.
  • 27. Aromatic Hydrocarbons (not assessed)
    • A special group of unsaturated cyclic hydrocarbons is known as arenes
      • contain single rings, or groups of rings
      • originally called “aromatic hydrocarbons”, because of pleasant odour
      • simplest arene is benzene (C 6 H 6 )
      • Term “aromatic” applies to materials with bonding like that of benzene
  • 28. Aromatic Hydrocarbons
    • Benzene is a six-carbon ring, with alternating double and single bonds
    • Benzene derivatives possible:
      • methylbenzene, 3-phenylhexane, ethylbenzene
      • Other commonly known aromatics are: napthalene, toluene, xylene, phenol.
      • Many aromatics are known carcinogens.
  • 29. General formulae
    • Alkane C n H 2n+2
    • Alkene C n H 2n
    • Alkyne C n H 2n-2
  • 30. Combustion of hydrocarbons
    • Complete combustion (excess air)
    • C n H 2n+2 + O 2 -> CO 2 + H 2 0
    • To balance:
      • Add 1 x O 2 for every C
      • Add ½ O 2 for every H 2
      • Check!
      • Try a few: CH 4 ; C 8 H 18 ; C 4 H 8 ;
  • 31. Summary – carbon chemistry
    • Hydrocarbons
    • Saturated – the alkanes – learn to C 10
    • Structure, naming, branching
    • Unsaturated – alkenes & - kynes
    • Cyclic and aromatic hydrocarbons
    • combustion

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