SPECIMEN

• Another structural isomer of J is shown below. Explain how the Cahn-Ingold-Prelog (CIP) priority rules can be used to deduce the full IUPAC name of this compound.

  STAGE 1

  • consider groups joined to RH carbon of C=C bond
  • consider atomic number of atoms attached
  • C has higher atomic number than H, so CH2OH takes priority

  STAGE 2

  • consider groups joined to LH carbon of C=C bond
  • both contain C atoms, so consider atoms one bond further away

  STAGE 3

  • conclusion
  • highest priority groups ethyl and CH2OH are on same side of C=C bond
  • so isomer is Z
  • rest of IUPAC name is 3-methylpent-2-en-1-ol
• In industry, this fermentation reaction is carried out at 35 °C rather than 25 °C. Suggest one advantage for industry of carrying out the fermentation at this higher temperature.

  Ethanol produced at a faster rate
• The method used by the student in Question 4.2 would result in the ethanol being contaminated by ethanoic acid. How does this contamination occur?

  Air gets in/ oxidation occurs
• Give two differences between the infrared spectrum of a carboxylic acid and that of an alcohol other than in their fingerprint regions. Use Table A on the Data Sheet.

  Alcohol OH absorption is different place from acid OH absorption

  C=O in acids has an absorption at 1680-1750cm(^-1)
• Which of these substances reacts most rapidly to produce a silver halide precipitate with acidified silver nitrate?

  A CH3Br

  B CH3Cl

  C CH3F

  D CH3I

  D
• Which statement about E-1,2-dichloroethene is correct?

  A It has the same boiling point as Z-1,2-dichloroethene.

  B It forms a polymer with the same repeating unit as Z-1,2-dichloroethene.

  C It has the same IR spectrum as Z-1,2-dichloroethene in the range 400–1500 cm–1.

  D It has a molecular ion peak different from that of Z-1,2-dichloroethene in its mass spectrum.

  B