• Functional group: hydroxyl group, \(-OH\)
  • General formula: \(C_nH_{2n+1}OH\)


Naming alcohol

  • Replacing the ‘e’ at the end of the alkane name with ‘ol’.
  • Example: methane to methanol.
  • For a longer alcohol chain, the position of the hydroxyl group is mentioned in the name of the alcohol. 


Name of alcohol Structural formula


Steps in naming an alcohol

  1. Determine the name of the main chain based on the number of carbon atoms in the longest and continuous carbon chain.
  2. The numbering of the main chain starts from the end closes to the hydroxyl group.
  3. Determine the position of the hydroxyl group in the main carbon chain.
  4. Determine the position of the branch chain.
  • Remember, priority is given to the hydroxyl group first, then the branch chain.


Physical properties of ethanol

  • A colourless solution at room temperature
  • Nice smell
  • Boiling point: 78°C
  • Volatile
  • Soluble in water


Uses of alcohol and its misuse



Daily life

  • Solvents for paints, sticker, ink, lacquer and varnish
  • Used as fuel


Production of chemicals such as ethanoic acid and ester


Cosmetics, perfumes, toothpaste and skin lotions


To make medicines