Chem- Organics

• Organic chemistry is the study of the chemistry of the element carbon.
• Functional Group


  The part of the molecule that determines its reactivity.
• Alkanes have single bonds
• Alkenes have one double bond
• Alkynes have one triple bond
• Alcohols -OH
• Haloalkanes have a halogen
• Amines -NH2
• Carboxylic acid -C-OH

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• Alkanes are they simplest forms of hydrocarbons. They are saturated (no spare bonds within the molecule for further atoms to be added). Alkanes are an homologous series. Their general formula is CnH2n+2
• Properties of Alkanes

  • Do not conduct
  • Insoluble in water
  • Non-polar
  • Low melting point
  • Melting point increases with size because the longer the molecule the greater the intermolecular attractive forces between molecules
  • Burns
• Naming Organic Compounds

  1. Count the number of carbon atoms in the longest chain
  2. Name the longest chain
  3. Name the functional group by adding a suffix
  4. Number the functional group with the smallest number
• Suffix


  alkanes -ane

  alkenes -ene

  alkynes -yne

  alcohols -ol

  haloalkane -ane

  carboxylic acids -oic acid

  amines -ane or amine
• Haloalkanes have a basic carbon chain with at least one hydrogen replaced with a halogen.
• Classifying Haloalkanes

  • Primary haloalkanes have one carbon atom bonded to the carbon with the halogen
  • Secondary haloalkanes have two carbon atoms bonded to the carbon with the halogen
  • Tertiary haloalkanes have three carbon atoms bonded to the carbon with the halogen
• Structural isomers have the same molecular formula but different structural formula.
• Geometric isomers can occur when a double bond is present. These isomers occur because there is no rotation about the double bond. Geometric isomers will only occur when there are two different atoms or groups on each carbon in the double bond.
• Cis isomer groups are on the same side of the double bond
• Trans isomer groups are on different sides of the double bond
• Alkenes are a homologous series of hydrocarbons where the molecule contains one or more double bonds between two adjacent carbon atoms. They are unsaturated because the double bond could be broken allowing further atoms to be bonded to the carbon atoms.
• Properties of Alkenes

  • Insoluble in water
  • Non-polar
  • Neutral
  • Does not conduct (no free electrons or ions)
• The general formula for alkenes is CnH2n
• Addition reaction is when the double bond in an alkene is 'added across' by a reagent that splits to put an atom or group of atoms on each of the two carbons in the double bond.
• Markovnikov's Rule


  When hydrogen halide or water add across a double bond, the hydrogen will bond to the carbon that has the most hydrogens already.

  "Rich get richer"
• Polymerisation

  • A polymer is a large molecule made up of many small molecules.
  • Polymerisation of alkenes involves the linking of many alkene molecules to form long chains.
  • Polymers are solids at room temperature and are mostly unreactive and resistant.
  • e.g. polyethene
• Alcohols are a homologous series of organic molecules consisting of an alkane chain with a hydroxyl (OH) group attached to one of the carbon atoms. The OH group replaces on of the hydrogen atoms.
• Physical Properties of Alcohols

  • Water soluble (solubility decreases as molecules get bigger due to polarity)
  • Polar (due to the OH functional group)
  • Neutral
• Reactions of Alcohols

  • Combustion
  • Oxidation
  • Substitution
  • Elimination
• Saytzeff's Rule


  The double bond will go between the carbon with the OH and the carbon with the fewest hydrogens

  'poor get poorer'
• Carboxylic acids are weak acids.
• During oxidation reactions, primary alcohols are oxidised to carboxylic acids, secondary alcohols are oxidised to ketones, and tertiary alcohols are not oxidised.
• During substitution reactions, a functional group is replaced by a different functional group.
• During elimination reactions, an alcohol is changed to an alkene and water is removed.