esters

• ethanol + ethanoic acid → ethyl ethanoate (ester) + H2O
• ETHYL ETHANOATE

  • Structural formula: CH3COOCH2CH3
• Esterification

  alcohol + carboxylic acid → ester + H2O

  • During esterification:
  • H is lost from the alcohol
  • OH is lost from the carboxylic acid
  • The parts are combined to form ester
• • Identify the acid and alcohol part:
  • Split the compound between two oxygens
  • Acid: the half with C=O
  • Alcohol: the half with O
  • Naming of ester:
  • Count the number of carbons in both acid and alcohol part
  • Alcohol part: -yl
  • Carboxylic acid: -oate
• USES OF ESTERS

  • Esters are volatile compounds with distinctive smells
  • Ester are often used as food flavourings and in perfumes
• METHODS

  1. Mix ethanol, ethanoic acid and concentrated sulphuric acid in a round-bottom flask
  2. Gently heat the mixture using a water bath or electric heater

  • Bunsen burner cannot be used because ethanol is flammable

  1. Ester formed is then distilled and collected to another beaker

  • Esters have lower boiling points, so they will evaporate first
  • Esters are removed from the mixture to prevent reverse reactions from occurring