industrial manufacturing techniques

  • continues process
  • batch process

production of aspirin

  • ethyl ethanoate and aspirin are produced by a batch process in industry

  • in a chemical plant large quantities of reactants are brought together in a reactor during which time the product is produced

  • after a certain time the reactor is emptied and the product is separated from the reaction mixture and purified

  • the product is then dried and packaged

  • esters and their manufacture

    • these have the functional group -COO-
    • they have the name -yl- anote eg methyl methoate
    • both R groups form part of the same

esters

  • esters are useful products
  • used as solvents
  • making polyesters
  • fruit smells are due to the presence of esters
  • ethyl ethanoate is used in glue and nail polish removers
  • ethyl ethanoate is used to remove caffeine from tea and coffee

manufacture

  • made by reacting ethanol with ethanoic acid
  • concentrated sulfuric acid is used as a catalyst
  • the reaction is slow and reversable
  • CH₃CH₂OH + CH₃COOH → CH₃COOCH₂CH₃ + H₂O
  • in industry the ester is made in a batch process
  • ethanol and ethanoic acid are added to a large reaction vessel together with the catalyst
  • the reaction mixture is heated
  • water produced during the rection is removed by distillation
  • yields of up to 95% are possible
  • other methods
    • Tishchenko reaction
    • liquid phase oxidation of butane
    • alkylation ethanoic acid with ethene (Avada process)

testing methods and techniques

  • boiling point determination
  • boiling point of pure substances are known very accurately and are listed in databases and books
  • the purity of a sample can be determined by comparing the boiling point of the sample to the actual value
  • boiling point occurs when the intermolecular bonds are broken
  • the greater the difference the more impurities are present
  • distillation can be used to determine boiling point
  • all values for boiling points are given as standard temperature and pressure

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