14.2 Reactions of alcohols

• Complete combustion of alcohols produces carbon dioxide and water
• Primary alcohols are oxidised to aldehydes by distilling with acidified potassium dichromate H+/Kr2Cr2O7

  • oxidising agent is written as [O]
  • chromium is reduced from +6 to +3 and solution changes from orange to green
• A primary alcohol is heated under reflux with excess oxidising agent to form a carboxylic acid

  • oxidising agent is written as 2[O]
• A secondary alcohol is heated under reflux with acidified potassium dichromate to form ketones
• Tertiary alcohols can't be oxidised
• Dehydrating agents such as concentrated sulfuric or phosphoric acid can be used to remove water from alcohols to form alkenes
• Removal of water from an alcohol is an example of an elimination reaction
• Alcohols react with halide ions in acidic conditions to produce haloalkanes and water

  • example of a substitution reaction