oxidation of alcohols

• how are types of alcohols distinguished?

  products of reaction with warm acidified potassium dichromate (which is orange)
• what are the products from main oxidation of alcohols?

  1° – aldehyde

  2° – ketone

  3° – n/a
• what are the products from further oxidation of alcohols?

  1° – carboxylic acid

  2° – n/a

  3° – n/a
• What is the colour change observed with alcohols and warm acidified potassium chromate?

  1° – orange to green

  2° - orange to green

  3° – n/a
• how are the oxidations completed?

  via distillation and reflux reactions
• why are anti-bumping granules used?

  prevent large bubbles forming
• why is water direction important in distillation?

  to ensure the condenser is completely filled
• what is necessary after distillation?

  collect aldehyde as soon as made to prevent further oxidation
• what is necessary in reflux reactions?

  ensure complete oxidation as aldehyde is produced

  it will drop back down into reaction mixture for second oxidation
• what does tollens reagent contain?

  silver nitrate and it is dissolved in ammonia
• what happens if an aldehyde is present with tollens reagent?

  silver ions reduced to silver metal and leave silver mirror

  aldehyde is oxidised to carboxylic acid
• what are the half equations for an aldehyde with tollens reagent?

  Ag+ + e- --> Ag

  CH3CHO + [O] --> CH3COOH
• what does fehlings solution contain?

  blue copper ions (Cu2+)
• what happens if an aldehyde is present with fehlings solution?

  aldehyde reduces the copper ions to Cu+

  aldehyde is oxidised to a carboxylic acid

  brick red precipitate formed