C10 organic reactions

• alkenes are less flammable than alkanes
• alkenes have incomplete combustion so have a smokier yellow flame
• alkanes have complete combustion
• alkenes release less energy per mole during combustion
• alkenes are more reactive than alkanes because of the carbon-carbon double bond
• the carbon carbon double bond in alkenes can be broken open to react with other molecules in electrophilic addition
• bromine water is used to test for unsaturated hydrocarbons
• hydrogenation


  alkenes can be reacted with hydrogen gas and a nickel catalyst to make alkanes
• hydrogenation is used to increase the melting point of unsaturated fats such as olive oil to make margarine
• why do unsaturated fats have a higher melting point after hydrogenation

  • stronger intermolecular forces
  • chains get closer together
  • more intermolecular forces
  • more energy required to overcome the forces
• alkenes can be reacted with steam to make alcohol
• reacting alkenes with steam to make alcohol

  • high temperatures
  • high pressures
  • expensive
  • reversible
• the homologous series of alcohols contains the -OH functional group
• the homologous series of carboxylic acid contains the -COOH functional group
• the homologous series of esters contains the -COO- functional group
• ethanol can produced by

  • fermentation
  • hydration of ethene
• fermentation

  • raw materials are reusable
  • lower energy needed for yeast
  • reuse yeast
  • have to separate/filter off yeast
  • land used for sugar cane/crops for fuel rather than food (deforestation)
  • fractional distillation to separate ethanol and water
  • lower atom economy
• hydration of ethene

  • crude oil is a finite resource
  • higher energy needed (300 degrees)
  • need to crack alkanes to make ethene (energy)
  • do no need to filter off yeast
  • unreacted ethene is recycled
  • fractional distillation to separate ethanol and water
  • 100% atom economy
• uses of alcohol

  • good solvents
  • spirits
  • dissolve substances
• reactions of ethanol

  • combustion in oxygen
  • reaction with sodium
• primary alcohols can be oxidised to carboxylic acid when heated under reflux with acidified potassium dichromate
• alcohols can be oxidised to a range of new groups
• heating under reflux


  when the reaction mixture is boiled using a vertical condenser so vapours cool and drip back into the reaction mixture
• esters are formed in a condensation reaction between alcohols and carboxylic acids
• condensation reaction


  two molecules react to form a larger molecule with the elimination of a smaller
• 1. measure 100cm3 of water. add it to the calorimeter
  2. take the initial temperature of the water
  3. measure the mass of the spirit burner
  4. light the spirit burner
  5. allow the temperature to increase by 10degrees
  6. stir continuously to dissipate the heat
  7. measure the mass of the spirit burner
  8. use E=mc t to calculate energy transferred
  9. find change in mass and calculate moles burnt