1 - Review all questions 2 answers  /28

    1)          Name the following molecule:  [1]

                               CH₃CHBrCH₂COOH

                                    3 - bromo butanoic acid

    2)          Describe a simple chemical test to distinguish between an alkane and an alkene. 

                 Include any observations. [3] 

                        Add bromine water   [1]

                        Stays orange with the alkane   [1]

                        Turns clear and colourless with the alkene   [1]

    3)          Show with the aid of curly arrows the mechanism for the reaction between hydrogen bromide and ethene [5] 

                                    Dipole on HCl  [1]

                                    Curly arrow from middle of C=C to d+ H  [1]

                                    Curly arrow from middle of H - Br to d- Br  [1]

                                    Correctly drawn carbocation  [1]

                                    Curly arrow from a pair of electrons on the Br ion to the positive carbon  [1]

    4)          Describe the type of reagent and mechanism for question 9   [2] 

                    Electrophilic  [1]  Addition [1]

    5)           Write an equation showing the initiation step for the reaction between chlorine and methane.

                  Describe the bond breaking.  [2]

                                Cl₂          à        Cl^.           +          Cl^.           UV light  [1]

                                Homolytic fission    [1]

    6)           For the reaction in (4), write out the propagation steps [2]

                                Cl^.    +    C₂H₆     à        HCl           +          ^.C₂H₅      [1]

                              ^.C₂H₅    +    Cl₂     à        C₂H₅Cl           +         Cl^.      [1]

    7)           For the reaction in (4), write out the termination steps [3]

                   Cl^.        +       Cl^.           à        Cl₂                  [1]

                   ^.C₂H₅    +       ^.C₂H₅       à        C₄H₁₀          [1]

                   Cl^.        +       ^.C₂H₅       à        C₂H₅Cl      [1]

    8)          Describe the type of reagent and mechanism for questions 4 - 6   [2] 

                    Free radical  [1]  Substitution [1]

    9)          Describe how you would convert propene to propane   [3]

                                  Hydrogen    [1]

                        Ni catalyst   [1]

                        150^oC         [1]

    10)        Describe how you would convert ethane to propanol   [2]

                                  Steam    [1]

                        H₃PO₄ / phosphoric acid   [1]

    11)        What type of reaction would convert hexane into benzene   [1]

                                  Reforming    [1]

    12)        Draw and label the stereoisomers of but - 2 - ene   [2]

Cis but-2-ene (Z-but-2-ene)     [1]	Trans but-2-ene (E-but-2-ene)     [1]