Organic Synthesis (OCR A Level Chemistry A): Exam Questions

Exam code: H432

3 hours31 questions
1
1 mark

CN ions react with haloalkanes and with carbonyl compounds.

Which row gives the correct mechanisms for the reactions?

 

Reaction of CN- with haloalkanes

Reaction of CN- with carbonyl compounds 

A

Electrophilic substitution 

Electrophilic addition

B

Electrophilic substitution 

Nucleophilic addition

C

Nucleophilic substitution 

Electrophilic addition

D

Nucleophilic substitution 

Nucleophilic addition

    2
    1 mark

    Phenylamine can be produced in a two-stage synthesis shown below.

    imT7nJgb_6-8-q2-phenylamine

    What is the correct classification of the steps?

     

    Step 1

    Step 2

    A

    Electrophilic substitution

    Reduction

    B

    Nucleophilic addition

    Reduction

    C

    Nitration

    Oxidation

    D

    Nucleophilic addition

    Oxidation

      3
      1 mark

      Propanal can be converted to propanoyl chloride via a two-stage synthesis route shown below.

      propanal  rightwards arrow with Step space 1 on top  propanoic acid  rightwards arrow with Step space 2 on top  propanoyl chloride

      What are the correct reagents for steps 1 and 2?

       

      Step 1

      Step 2

      A

      H2O / HCl

      SOCl2

      B

      NaBH4 / H2O

      H2O / HCl

      C

      K2Cr2O7 / H+

      SOCl2

      D

      K2Cr2O7 / H+

      H2O

        4
        1 mark

        Many organic products can be synthesised from a few starting compounds using the correct reagents and conditions.

        Which skeletal formula is a correct example for the functional groups stated?

         

        Functional groups

        Example

        A

        Alcohol and nitrile

        6-8-q4-a

        B

        Alcohol and nitrile

        6-8-q4-b

        C

        Ester and alkene

        6-8-q4-c

        D

        Carbonyl and haloalkane

        6-8-q4-d
          5
          1 mark

          Which of the following compounds can not be formed directly from an alcohol?

          • Amine

          • Ester

          • Alkene

          • Ketone

          1
          1 mark

          The structure of the amino acid phenylalanine is shown below.

          phenylalanine

          Which functional group(s) is / are in a molecule of phenylalanine?

          1. Amine

          2. Amide

          3. Alcohol

          • 1, 2 and 3

          • Only 1 and 2

          • Only 2 and 3

          • Only 1

          2
          1 mark

          Which statement about melting point tests is not correct?

          • Impurities can raise or lower the melting point of organic solids

          • The melting point tubes must be heated slowly

          • Organic solids with high melting points can decompose before melting

          • The organic solid must be finely powdered and dry

          3
          1 mark

          The synthesis of ethyl butanoate can be carried out using the reaction scheme shown below.

                                  C4H9Br   rightwards arrow with Step space 1 on top  C4H9OH  rightwards arrow with Step space 2 on top  C3H7COOH  rightwards arrow with Step space 3 on top  C3H7COOC2H5  

          What is the correct classification of the steps?

           

          Step 1

          Step 2

          Step 3

          A

          Substitution

          Oxidation

          Condensation

          B

          Addition

          Substitution

          Condensation

          C

          Oxidation

          Substitution

          Condensation

          D

          Substitution

          Oxidation

          Substitution

            4
            1 mark

            Propanone can be converted to 2-bromopropane using the three step synthetic scheme shown below. 

            Propanone rightwards arrow with Step space 1 on top propan-2-ol rightwards arrow with Step space 2 on toppropene rightwards arrow with Step space 3 on top2-bromopropane

            What are the correct reagents for each step?

             

            Step 1

            Step 2

            Step 3

            A

            K2Cr2O7 / H2SO4

            Conc. NaOH

            HBr

            B

            NaBH4

            Al2O3

            HBr

            C

            H2O / H2SO4

            Al2O3

            Br2

            D

            NaBH4

            K2Cr2O7 / H2SO4

            HBr

              5
              1 mark

              Butylamine can be prepared in two steps from 1-bromopropane

              CH3CH2CH2Br → X → CH3CH2CH2CH2NH2

              What is the structural formula of X?

              • CH3CH2CH2OH

              • CH3CH=CH2

              • CH3CH2CH2CN

              • CH3CH2CH2CHO

              1
              1 mark

              Which row contains the correct number of minimum steps to convert an aldehyde into the given compound?

               

              Amide

              Primary amine

              Dihalogenoalkane

              A

              2 steps

              3 steps

              4 steps

              B

              4 steps

              2 steps

              3 steps

              C

              3 steps

              4 steps

              2 steps

              D

              2 steps

              3 steps

              3 steps

                2
                1 mark

                Propyl 4-aminobenzoate or risocaine is a local anesthetic that can be synthesised from 4-nitrobenzaldehyde via the following three step synthesis.

                nwnKtwWD_7-8-h-q1-mcq-aqa-al-chemistry

                Which row contains the correct molecular formulae of compounds X and Y?

                 

                Compound X

                Compound Y

                A

                C7H6NO3

                C9H11NO4

                B

                C7H6NO4

                C10H11NO3

                C

                C7H5NO4

                C10H11NO4

                D

                C7H5NO3

                C9H11NO3

                  3
                  1 mark

                  Which statement about the purification of an organic solid is not correct?

                  • Recrystallisation uses a solvent in which the organic solid dissolves when hot but will crystallise out when cold. 

                  • Hot filtration can be used after recrystallisation to remove any solid impurities that remain. 

                  • Impurities tend to lower the melting point of organic solids such as aspirin. 

                  • A water bath can be used to determine the melting point of the organic solid. 

                  4
                  1 mark

                  Below is a sequence of reactions from the starting molecule bromopropane.

                  l4hQIC9o_ocr-a2-6-8h-mcq-q2-reaction-sequence

                  Which reagent or type of mechanism is not correct for the indicated step?

                  • Step 1 NaCN / Nucleophilic substitution

                  • Step 2 H2O/HCl / Hydrolysis

                  • Step 3 SOCl2 / Chlorination 

                  • Step 4 methylamine / Nucleophilic substitution 

                  5
                  1 mark

                  A reaction sequence starting from ethene is shown below.

                  ocr-a2-6-8h-mcq-q3-reaction-sequence

                  Which statement(s) is/are correct?

                  1. Two of the molecules belong to the same homologous series.

                  2. Reaction 4 produces a compound that will conduct electricity in the molten state.

                  3. Reactions 1, 2, 3 and 5 require sulfuric acid. 

                  • 1, 2 and 3

                  • Only 1 and 2

                  • Only 2 and 3

                  • Only 1