Alcohols

• General formula:

  CnH(2n+1)OH
• Functional group:

  -OH (Hydroxyl group).
• 4 smallest alcohols:

  Methanol (CH3OH)

  Ethanol (CH3CH2OH)

  Propanol (CH3CH2CH2OH)

  Butanol (CH3CH2CH2CH2OH)
• Alcohols combust, releasing energy. We can measure this energy by measuring the temperature change in water.
• Must consider:

  • Heat can be lost to surroundings (use a draught insulator to minimise).
  • Some water evaporates.
  • Heat energy is used to heat up glass before heating water.
• When alcohols react with a strong oxidising agent, a carboxylic group is formed.
• When alcohols react with air and heat, carbon dioxide and water are produced.

  • 2CH3OH(l) + 3O2(g) → 2CO2(g) + 4H2O(l)
• When alcohols react with water, they dissolve to give a neutral solution.
• When alcohols and sodium react, hydrogen is produced.