Organic chemistry

• Homologous series


  Series of organic compounds with the same general formula and similar chemical properties
• Alkanes


  Saturated hydrocarbons with the general formula CnH2n+2
• Alkenes


  Unsaturated hydrocarbons with the general formula CnH2n
• Alcohols


  Organic compounds with the general formula CnH2n+1OH
• Functional group


  Specific group of atoms within a molecule that determines the chemical properties
• Ethane


  Alkane with 2 carbon atoms and the formula C2H6
• Ethene


  Alkene with 2 carbon atoms and the formula C2H4
• Ethanol


  Alcohol with 2 carbon atoms and the formula C2H5OH
• Hydrocarbons


  • Saturated
  • Unsaturated
• Isomerism


  When two molecules have the same molecular formula but different structures
• Butane


  Alkane with 4 carbon atoms and the formula C4H10
• Methylpropane


  Isomer of butane with a methyl group attached
• Properties of homologous series

  • Melting and boiling point increase as number of carbon atoms increase
  • Solubility in water decreases as number of carbon atoms increase
  • Can be represented by a general formula
• Combustion


  Chemical reaction where a substance reacts with oxygen to release heat and form products
• Complete combustion


  1. Enough oxygen

  2. Reactants form CO2 and H2O
• Incomplete combustion


  1. Not enough oxygen

  2. Reactants form CO and H2O
• Substitution reaction


  One group of atoms is replaced by another group
• Substitution reactions


  • CH4 + Cl2 -> CH3Cl + HCl
• Addition reaction


  Two reagents add across a double bond to form a single product
• Addition reactions


  • C2H4 + Br2 -> C2H4Br2
• Test for unsaturation


  Bromine water is decolourised
• Carboxylic acids


  Organic compounds with the general formula CnH2n+1COOH
• Reactions of carboxylic acids

  1. With metals

  2. With bases

  3. Oxidation
• Esterification


  Reaction between an alcohol and a carboxylic acid to form an ester
• Polymers


  Large molecules built up from many smaller monomer units
• Addition polymerisation


  Monomers join together in a chain reaction
• Condensation polymerisation


  Two monomers join together, releasing a small molecule like water
• Polyethene/polythene


  Addition polymer made from ethene monomers
• Polyvinyl chloride


  Addition polymer made from vinyl chloride monomers
• Polystyrene


  Addition polymer made from styrene monomers
• Polyester


  Condensation polymer made from dicarboxylic acids and diols
• Polyamide


  Condensation polymer made from diamines and dicarboxylic acids
• Environmental challenges caused by plastics include disposal in landfill sites, accumulation in oceans, and formation of toxic gases from burning
• Plastics can accumulate up the food chain