Organic Synthesis (OCR A Level Chemistry)

Exam Questions

3 hours31 questions
11 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

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    21 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

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      31 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

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        41 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

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          51 mark

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

          • Amine

          • Ester

          • Alkene

          • Ketone

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          11 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

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          21 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

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          31 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

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            41 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

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              51 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

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              11 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

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                21 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

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                  31 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. 

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                  41 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 

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                  51 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

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