Alcohols

• Primary alcohols can undergo oxidation reactions to form aldehydes or carboxylic acids.

  
  

  A aldehyde is formed when a primary alcohol is heated with [O] under distillation

  
  

  A carboxylic acid is formed when a primary alcohol is heated with [O] under reflux
• Alcohols combust completely in an excess of oxygen to produce CO₂ and H₂O
• Alcohols can be dehydrated by heating under reflux in the presence of an acid catalyst such as H₃PO₄ or H₂SO₄
• When alcohols react with hydrogen halides a substituiton reaction occurs in which the halogen atom substitutes with the OH group of the alcohol.

  The alcohol is heated under reflux with sulfuric acid and a sodium halide, producing the hydrogen halide in situ. The halide then reacts with the alcohol forming a halogen alkane.
• Primary and secondary alcohols can be oxidised by heating with an oxidising agent, most commonly acidified potassium dichromate(VI).

  Colour change of Orange to Green

  Tertiary alcohols are not oxidised.
• When secondary alcohols are heated with [O] under reflux or distillation a ketone is produced.